Analysis of Thermoset Materials, Precursors and Products (Rapra review reports) (v. 14, No. 6)

Rapra Review Reports

Report 162

ISSN: 0889-3144

Analysis of Thermoset Materials, Precursors and Products M.J. Forrest

Volume 14, Number 6, 2003

Rapra Review Reports Expert overviews covering the science and technology of rubber and plastics

RAPRA REVIEW REPORTS A Rapra Review Report comprises three sections, as follows: 1. A commissioned expert review, discussing a key topic of current interest, and referring to the References and Abstracts section. Reference numbers in brackets refer to item numbers from the References and Abstracts section. Where it has been necessary for completeness to cite sources outside the scope of the Rapra Abstracts database, these are listed at the end of the review, and cited in the text as a.1, a.2, etc. 2. A comprehensive References and Abstracts section, resulting from a search of the Rapra Polymer Library database. The format of the abstracts is outlined in the sample record below. 3. An index to the References and Abstracts section, derived from the indexing terms which are added to the abstracts records on the database to aid retrieval.

Source of original article Title

Item 1 Macromolecules

33, No.6, 21st March 2000, p.2171-83 EFFECT OF THERMAL HISTORY ON THE RHEOLOGICAL BEHAVIOR OF THERMOPLASTIC POLYURETHANES Pil Joong Yoon; Chang Dae Han Akron,University The effect of thermal history on the rheological behaviour of ester- and ether-based commercial thermoplastic PUs (Estane 5701, 5707 and 5714 from B.F.Goodrich) was investigated. It was found that the injection moulding temp. used for specimen preparation had a marked effect on the variations of dynamic storage and loss moduli of specimens with time observed during isothermal annealing. Analysis of FTIR spectra indicated that variations in hydrogen bonding with time during isothermal annealing very much resembled variations of dynamic storage modulus with time during isothermal annealing. Isochronal dynamic temp. sweep experiments indicated that the thermoplastic PUs exhibited a hysteresis effect in the heating and cooling processes. It was concluded that the microphase separation transition or order-disorder transition in thermoplastic PUs could not be determined from the isochronal dynamic temp. sweep experiment. The plots of log dynamic storage modulus versus log loss modulus varied with temp. over the entire range of temps. (110-190C) investigated. 57 refs.

Location

GOODRICH B.F. USA

Authors and affiliation

Abstract

Companies or organisations mentioned

Accession no.771897

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Molecular Weight Characterisation of Synthetic Polymers, S.R. Holding and E. Meehan, Rapra Technology Ltd. and Polymer Laboratories Ltd.

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Polymer Product Failure, P.R. Lewis, The Open University.

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Ring Opening Polymerisation, N. Spassky, Université Pierre et Marie Curie.

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Analysis of Thermoset Materials, Precursors and Products

Martin J. Forrest (Rapra Technology Limited)

ISBN 1-85957-390-8

Analysis of Thermoset Materials, Precursors and Products

Contents 1.

Introduction .............................................................................................................................................. 5

2.

Thermoset Products ................................................................................................................................ 5

3.

4.

2.1

Thermoset Polymer Systems .......................................................................................................... 5

2.2

Basic Chemistry .............................................................................................................................. 5

2.3

Additives Used in Thermosets ........................................................................................................ 7 2.3.1 Organic Modifiers .............................................................................................................. 7 2.3.2 Fillers .................................................................................................................................. 8 2.3.3 Antidegradants/Stabilisers .................................................................................................. 8 2.3.4 Curing Species (e.g., Hardeners and Accelerators) ............................................................ 9 2.3.5 Flame Retardants .............................................................................................................. 10 2.3.6 Lubricants ......................................................................................................................... 10 2.3.7 Miscellaneous Additives .................................................................................................. 10

Overview of Analytical Techniques .......................................................................................................11 3.1

Wet Chemistry Techniques ............................................................................................................11

3.2

Spectroscopic Techniques ............................................................................................................. 12 3.2.1 Infrared Spectroscopy (IR) ............................................................................................... 12 3.2.2 Ultraviolet Light Spectroscopy (UV) ............................................................................... 12 3.2.3 Nuclear Magnetic Resonance Spectroscopy (NMR) ....................................................... 12 3.2.4 Atomic Absorption Spectroscopy (AAS) ......................................................................... 12 3.2.5 X-Ray Fluorescence Spectroscopy (XRF) ....................................................................... 12 3.2.6 Raman Spectroscopy ........................................................................................................ 12

3.3

Chromatographic Techniques ....................................................................................................... 13 3.3.1 Gas Chromatography-Mass Spectrometry (GC-MS) ....................................................... 13 3.3.2 Gas Chromatography (GC) .............................................................................................. 13 3.3.3 High Performance Liquid Chromatography (HPLC) ....................................................... 13 3.3.4 Liquid Chromatography-Mass Spectroscopy (LC-MS) ................................................... 13 3.3.5 Gel Permeation Chromatography (GPC) ......................................................................... 14 3.3.6 Thin Layer Chromatography (TLC) ................................................................................. 14 3.3.7 Supercritical Fluid Chromatography (SFC) ..................................................................... 14

3.4

Thermal Techniques ...................................................................................................................... 14 3.4.1 Differential Scanning Calorimetry (DSC) ....................................................................... 14 3.4.2 Dynamic Mechanical Thermal Analysis (DMTA) ........................................................... 14 3.4.3 Thermal Mechanical Analysis (TMA) ............................................................................. 15 3.4.4 Thermogravimetric Analysis (TGA) ................................................................................ 15 3.4.5 Dielectric Analysis (DEA) ............................................................................................... 15

3.5

Elemental Techniques ................................................................................................................... 17

3.6

Microscopy Techniques ................................................................................................................ 17

3.7

Miscellaneous Techniques ............................................................................................................ 17

Characterisation of Thermoset Polymers and their Precursors ....................................................... 17 4.1

Determination of the Molecular Weight of Thermoset Precursors and the Separation of their Oligomers ......................................................................................................................... 17

1

Analysis of Thermoset Materials, Precursors and Products

4.1.1 4.1.2 4.1.3 4.1.4 4.1.5 4.1.6 4.2

Polymer Type and Microstructure ................................................................................................ 23 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5

5.

7.

8.

2

Infrared Spectroscopy....................................................................................................... 23 NMR Spectroscopy .......................................................................................................... 26 Identifying Functional Groups ......................................................................................... 27 Pyrolysis Gas Chromatography ........................................................................................ 27 Thermal Analysis Techniques .......................................................................................... 28

Determination of Organic Modifiers and Fillers in Thermoset Products ....................................... 28 5.1

Determination of Organic Modifiers ............................................................................................ 28

5.2

Determination of Fillers ................................................................................................................ 29 5.2.1 5.2.2

6.

Gel Permeation Chromatography ..................................................................................... 18 Liquid Chromatography Techniques ................................................................................ 19 Epoxy Resins .................................................................................................................... 20 Polyurethane ..................................................................................................................... 22 Microbore-GPC ................................................................................................................ 22 Other Techniques .............................................................................................................. 22

Particulate Fillers .............................................................................................................. 29 Fibrous Fillers ................................................................................................................... 30

Determination of Functional Additives in Thermoset Products ....................................................... 31 6.1

Antidegradants .............................................................................................................................. 31

6.2

Flow Promoters and Flexibilisers ................................................................................................. 32

6.3

Pigments ........................................................................................................................................ 32

6.4

Blowing Agents............................................................................................................................. 33

6.5

Flame Retardants .......................................................................................................................... 33

6.6

Curing Systems ............................................................................................................................. 34

Cure Behaviour Studies ........................................................................................................................ 36 7.1

Dielectric Analysis ........................................................................................................................ 36

7.2

Differential Scanning Calorimetry ............................................................................................... 37

7.3

Dynamic Mechanical Thermal Analysis/Dynamic Mechanical Analysis .................................... 39

7.4

Thermal Mechanical Analysis ...................................................................................................... 39

7.5

Scanning Vibrating Needle Curemeter ......................................................................................... 40

7.6

Chromatography Techniques ........................................................................................................ 41

7.7

Spectroscopy Techniques .............................................................................................................. 41

7.8

Thermally Stimulated Depolarisation ........................................................................................... 42

7.9

Wet Chemistry Techniques ........................................................................................................... 43

Surface Analysis of Thermosets ........................................................................................................... 43 8.1

X-Ray Photoelectron Spectroscopy (XPS) ................................................................................... 43

8.2

Laser Induced Mass Analysis (LIMA) ......................................................................................... 44

8.3

Secondary Ion Mass Spectroscopy (SIMS) .................................................................................. 44

Analysis of Thermoset Materials, Precursors and Products

9.

Failure Diagnosis ................................................................................................................................... 45 9.1

Compositional Problems ............................................................................................................... 45

9.2

Heat Ageing .................................................................................................................................. 45

9.3

Contamination Problems .............................................................................................................. 45 9.3.1 Solid Contaminants .......................................................................................................... 45 9.3.2 Liquid Contaminants ........................................................................................................ 45

9.4

Odour and Emissions Problems .................................................................................................... 46

10. Conclusion .............................................................................................................................................. 46 Additional References ................................................................................................................................... 47 Abbreviations and Acronyms ....................................................................................................................... 48 Abstracts from the Polymer Library Database .......................................................................................... 51 Subject Index ............................................................................................................................................... 135 Company Index ............................................................................................................................................ 145

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3

Analysis of Thermoset Materials, Precursors and Products

4

Analysis of Thermoset Materials, Precursors and Products

1 Introduction This Rapra Review Report completes a series of three that overview the chemical analysis of the three principal polymer classes; the other two cover rubbers (54) and thermoplastics (17). All three product types present the analyst with considerable challenges due to their complexity and the wide range of polymer types and additives available. Of the three groupings, thermosets represent the most versatile in terms of the range of products that can be manufactured from them. As an illustration, the types of products that can be produced from thermosetting systems include: • • • • • • • •

Mouldings Resins Adhesives Coatings (e.g., lacquers and varnishes) Inks Paints Cements Composites

It is the availability of a large range of reactive chemicals that have the potential to generate three dimensional matrices which is responsible for this diversity as well as the development of specific technologies for the particular groups. The chemistry of thermosets is a mature one, with the advent of phenolics, the first truly man-made resin, going back nearly 110 years and predating the advent of thermoplastics by many years. The statistics describing the usage of thermosets belie their relatively low profile. They are an extremely important product group comprising 25% of the world’s total plastics production (16). Within this figure, polyurethanes have the largest share accounting for 34%, with urea-formaldehydes at 32%, phenol-formaldehydes at 15%, unsaturated polyesters at 9%, epoxy resins at 5%, melamine-formaldehyde at 4% and the furans and miscellaneous others taking up the remaining 1%. The objective of this review is to present, as fully as is possible within this format, an introduction to the analytical techniques and methods that are used to characterise and carry out quality control work on thermosets, investigate the failure of thermoset products and to deformulate thermoset compounds. With respect to the last category, the analyst’s job when characterising ‘unknowns’ is always made much easier

if at least some information is available on the sample and the types of species that may be present in it. Armed with this knowledge they can work much more efficiently and obtain better results. To assist in the acquisition of this knowledge opportunities have been taken within the text to not only detail the analytical methods, but provide examples of the species that they may be used to detect and quantify. In other words, in order to have a full understanding of the principle behind, and surrounding, the analytical methods and approaches it is vital to have an understanding of thermoset technology itself. Relevant books and academic papers are cited throughout the review, but there are also a number of general texts which will provide useful further reading (17, 54, 70, 78, 129, 202, 213, 214, 313, 395, a.1-a.7). A list of examples of standards relating to thermoset analysis is shown in Table 1.

2 Thermoset Products 2.1 Thermoset Polymer Systems The wide variety of thermoset products that can be made using reactive monomers and prepolymers (or polymers) is matched by the range of chemical compounds that can behave in this way. The list in Table 2 covers the best known examples. Table 2 illustrates the most popular and commonly used reactants. In many cases (e.g., polyurethanes) a large choice of reactive species is available to produce variants of the polymer with respect to hardness, process viscosity, strength, etc., and specialist properties such as flame retardancy where flame retardant reactive monomers are employed. In each case an associated technology, quite often in a very mature state reflecting the length of time that the material has been available, has grown up to optimise the manufacturing characteristics and service performance of each product group.

2.2 Basic Chemistry Thermosets have a three dimensional crosslinked structure and so, unlike thermoplastics, will not deform

5

Analysis of Thermoset Materials, Precursors and Products

Table 1 Examples of thermoset standards BS 2554

1999

Plastics. Unsaturated polyester resin. Determination of hydroxyl value.

BS 2782-4: Methods 451F to 451J

1978

Methods of testing plastics. Chemical properties. Determination of formaldehyde in phenolic mouldings (colorimetric method). Determination of formaldehyde in phenolic mouldings (gravimetric method). Determination of sulphates in phenolic mouldings.

BS 2782-4: Method 432A

1991

Methods of testing plastics. Chemical properties. Determination of residual styrene monomer content in reinforced plastics based on unsaturated polyester resins

BS EN 1240

1998

Adhesives. Determination of hydroxyl value and/or hydroxyl content.

BS EN 1242

1998

Adhesives. Determination of isocyanate content.

BS EN 12192

1999

Production and systems for the protection and repair of concrete structures test methods. Granulometry analysis. 2: Test methods for fillers for polymer bonding agents.

BS EN 12963

2001

Adhesives. Determination of free monomer content in adhesives based on synthetic polymers.

BS EN ISO 119

1998

Plastics. Phenol-formaldehyde mouldings. Determination of free phenols. Iodometric method

BS EN ISO 120

1998

Plastics. Phenol-formaldehyde mouldings. Determination of free ammonia and ammonium compounds. Colorimetric comparison method

BS EN ISO 172

1998

Plastics. Phenol-formaldehyde mouldings. Detection of free ammonia

BS EN ISO 3001

1999

Plastics. Epoxy compounds. Determination of epoxy equivalent

BS EN ISO 4614

2000

Plastics. Melamine-formaldehyde mouldings. Determination of extractable formaldehyde

BS EN ISO 9020

1994

Binders for paints and varnishes — Determination of free-formaldehyde content of amino resins — Sodium sulfite titrimetric method

BS EN ISO 9397, BS 2782-4: Method 451N 1997

1995

Plastics – Phenolic resins – Determination of free-formaldehyde content – Hydroxylamine hydrochloride method

BS EN ISO 10363

1995

Hot-melt adhesives. Determination of thermal stability.

BS EN ISO 11376

2001

Plastics. Epoxy resins and glycidyl esters. Determination of inorganic chlorine

BS EN ISO 11402

1998

Plastics. Condensation resins. Determination of free formaldehyde

BS EN ISO 11908

1998

Binders for paints and varnishes. Amino resins. General methods of test.

BS EN ISO 14896

2001

Plastics. Polyurethane raw materials. Determination of isocyanate content.

BS ISO 14848

1998

Plastics. Unsaturated polyester resins. Determination of reactivity at 130 °C.

ISO 2114

1996

Plastics. Unsaturated polyester resins. Determination of partial acid value and total acid value.

ISO 2535

1997

Plastics. Unsaturated polyester resins. Measurement of gel time at 25 °C.

ISO 2554

1997

Plastics. Unsaturated polyester resins. Determination of hydroxyl value.

ISO 3451-1

1997

Plastics – Determination of ash – Part 1: General methods.

NF EN ISO 8988

April 1997

Plastics. Phenolic resins, determination of HTMA content by the Kjeldahl method.

NF EN ISO 2114

March 1997

Plastic materials. Unsaturated polyester resins, determination of acid value.

NF EN ISO 4583

July 1998

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Plastics. Epoxy resins and related materials, determination of easily saponifiable chlorine.

Analysis of Thermoset Materials, Precursors and Products

Table 2 Common thermoset systems Polymer

Produced from

Phenol-formaldehyde

Phenol and formaldehyde

Melamine-formaldehyde

Melamine and formaldehyde

Urea-formaldehyde

Urea and formaldehyde

Resorcinol-formaldehyde

Resorcinol and formaldehyde

Epoxy resins

Bisphenol A and epichlorohydrin

Polyurethanes

Diisocyanate and a polyol

Polyalkyd resins

Glycerol and phthalic acid in the presence of fatty acid oils such as linseed oil

Silicone resins

Hydrolysis of chlorosilanes

Polyester resins

Unsaturated acid and alcohol compounds usually with a reactive diluent such as styrene

Acrylic resins

Di and poly functional acrylic monomers

Furan resins

Resinification of either furfural or furfuryl alcohol

Polyimides

Pyromellitic dianhydride with a difunctional aromatic amine

and flow under the influence of heat. This type of structure can be formed in a number of ways, including: 1. Condensation type polymerisation by systems in which at least one of the monomers or oligomer precursors has a functionality greater than two. Examples of this type of material include silicone resins, aminoplastics and phenolics. 2. The use of a crosslinking species to form crosslinks between polymer molecules. Examples of this type of material include epoxy resins where the crosslinking species can be a difunctional amine and unsaturated polyesters where it is styrene monomer. 3. The addition polymerisation of monomers containing two double bonds. An example of this type of material is polymerised diallyl phthalate. It is normally the case that materials that are formed by the first mechanism are produced in two stages. In the first stage relatively low molecular weight polymers are formed. These can be solid materials in their own right and are regarded as low molecular weight precursors to the final product. Two important commercial examples of such a product are the novolac and resol resins that are produced by the reaction of phenol and formaldehyde under acidic and basic conditions, respectively. These resins, which are comparatively stable at room temperature, are formed

into the desired shape and then under the influence of heat or catalysts the molecules react together to form crosslinks. The term thermoset derived from the early forms of these types of material (e.g., phenolic resins) where heat was always needed to produce the final crosslinked resin. These days heat is not always a prerequisite and crosslinking can occur at normal ambient temperatures, by the use of catalysts (e.g., certain adhesives and sealants) or the influence of an energy source such as ultraviolet light (e.g., acrylic dental cements). It can be seen from the list give in Section 2.1 that the term thermoset covers a large range of polymeric materials. This flexibility of thermosetting systems has been used to produce a very wide range of products from soft sealants and mastics, to hard resins and adhesives, to coatings and paints.

2.3 Additives Used in Thermosets 2.3.1 Organic Modifiers The use of plasticiser type compounds in thermosets is not common, but there are a number of organic compounds used for purposes such as flow promotion in the production of low shrinkage mouldings from highly condensed resins which undergo little cure in the mould. In the case of phenolics, compounds used for flow

7

Analysis of Thermoset Materials, Precursors and Products

promotion include, naphthalene, furfural and dibutyl phthalate and are added at around the 1% w/w level. Epoxy resins usually contain organic modifiers to address two of the disadvantages of the materials: high viscosity and excess rigidity for certain applications. To assist with flow, reactive diluents such as phenyl glycidyl ether, butyl glycidyl ether and octylene oxide are used. In order to increase flexibility, polymeric plasticisers have been used. Examples include low molecular weight polyamides, low molecular weight polysulfides, polyamines and the polyglycol diepoxides. It is also the case that rubber modifiers can be used in some thermoset products such as phenol-formaldehyde resins and epoxy resins. To overcome the brittleness of certain adhesive compounds (e.g., acrylics) it is common to blend them with rubbery polymers or polyurethanes. These modifiers often contain unsaturated groups so that they are grafted into the polymer matrix during crosslinking. In the case of urea-formaldehyde resins, glyceryl tolyl ether is used as a flow promoter in some low mould shrinkage formulations. To improve the adhesion properties of furan resins to substrates such as wood and metal, ‘plasticisers’ such as polyvinyl acetate and polyvinyl formal can be added to the products.

(e.g., barium sulfate) or electrical insulation (e.g., ironfree mica powder), or reduction in curing exotherms (e.g., metal powders in epoxies). Carbon based fillers such as carbon black and graphite are also used. The former as a diluent or pigment material and the latter to reduce friction, and hence wear, in service, or to impart a degree of conductivity.

2.3.2.2 Fibrous Fibrous fillers have been used for a long time in thermosets, particularly moulded products. Wood flour, coconut shell flour, cotton flock (15), macerated fabric and paper, and short lengths of synthetic fibres such as nylon can improve the strength and often rigidity and toughness of moulding compositions. Inorganic fibres such as asbestos and glass fibre are also used in moulding compositions where heat resistance and strength, respectively, are required. Chopped carbon fibres and whiskers (single crystals of high lengthdiameter ratio of very high strength) have also been used in specialist applications. Fibres are used extensively in phenolic, aminoplastics, epoxy and polyester based products. Often coupling agents are used with glass fibres to improve the adhesion between the surface of the glass and the polymer. These coupling agents tend to be silanes such as glycidoxypropyl trimethylsilane (used in phenolic, epoxy and polyester products) or triethoxyvinylsilane (used in polyesters).

2.3.2 Fillers Fillers are widely used in thermosets to alter physical properties such as hardness, modulus and creep. The main types are as follows:

It is also the case that thermoset polymers (e.g., polyimides and melamine-formaldehyde) are commonly encountered in laminate materials, where the substrates such as glass and carbon fibre have been impregnated with the resin prior to crosslinking.

2.3.2.1 Particulate

2.3.2.3 Miscellaneous

In this group fall inorganic fillers such as silica, silicates (e.g., clay), calcium carbonate and barium sulfate. Unlike rubbers where specific rubber-filler interactions and the much lower crosslink density can result in the smaller particle size inorganic raising physical properties such as tensile strength and tear strength, the presence of these fillers in thermosets does not usually improve such properties. These fillers are therefore used for purposes such as reduction in cost (e.g., calcium carbonate), increase in wear resistance (e.g., silica or sand), improved chemical resistance

A number of other filler type materials are used in thermoset products such as bleached wood pulp and chopped regenerated cellulose (both used in ureaformaldehyde resins).

8

2.3.3 Antidegradants/Stabilisers Most of the thermoset polymers possess a relatively high degree of resistance to degradation agencies such as ozone, oxygen and heat. In fact, thermosets such as

Analysis of Thermoset Materials, Precursors and Products

melamine-formaldehyde are very thermally stable and this property is exploited to produce heat resistant work surfaces. This stability relates to the relatively high proportion of aromatic hydrogens in the molecules (less easily abstracted than aliphatic hydrogens to form free radicals on the polymer backbone), the stability of the chemical bonds (e.g., Si-O) and the low concentration of points of attack such as double bonds. It is therefore less common for these materials to contain this type of additives than members of the other two major polymer groups, the thermoplastics or elastomers.

2.3.4.4 Resorcinol-Formaldehyde Adhesives Novolac type resins are usually hardened by paraformaldehyde in conjunction with an accelerator such as magnesium oxide.

2.3.4.5 Unsaturated Polyester Resins Crosslinkers:

Methyl ether ketone peroxide or cyclohexanone peroxide (ambient cures)

However, there is a place for these types of additives in certain systems. For example, hexamine has been used as a stabiliser in urea-formaldehyde resins, tetravalent tin compounds and organic phosphites have been used in polyurethanes.

2.3.4 Curing Species (e.g., Hardeners and Accelerators) The different classes of thermosets have evolved using specific technologies and so the types of curative species present can vary considerably. Examples of the curing system species used in a number of thermoset polymers are:

Benzoyl peroxide (high temperature cures)

Acetyl acetone peroxide (top coats and thin sections at low ambient temperatures) Accelerators:

Dimethylaniline (high and low temperature cures) Cobalt naphthenate or octoate (ambient cures)

Cure inhibitors to control gelling: Tertiary butyl catechol

2.3.4.1 Phenol-Formaldehyde Moulding Powders 2.3.4.6 Epoxy Resins Catalyst:

Oxalic acid

Hardener:

Hexamethylene triamine (‘Hexa’)

Accelerators: Basic compounds such as calcium oxide or magnesium oxide

The crosslinking of epoxy resins may be carried out either through the epoxy group or the hydroxyl groups. Two types of curing agent may also be distinguished, catalytic systems and polyfunctional crosslinking agents. Some compounds (e.g., amines) may behave as both types of species.

2.3.4.2 Urea-Formaldehyde Resins Accelerator:

‘Latent acid’ compounds such as ammonium sulfamate, ammonium phenoxyacetate, ethylene sulfite and trimethyl phosphate

2.3.4.3 Melamine-Formaldehyde Resins Reaction catalyst: Triethanolamine (electrical grade laminates) Sodium carbonate (general purpose laminate)

2.3.4.7 Amine Hardening Systems These come in a number of forms including primary aliphatic amines (e.g., diethylene triamine), aliphatic amine adducts (e.g., amine-glycidyl adducts and cyanoethylation products), aromatic amines (e.g., mphenylenediamine and diaminophenyl sulfone), cyclic aliphatic amines (e.g., piperidine) and tertiary amines (e.g., triethylamine and tri(dimethylaminomethyl) phenol). In some applications (e.g., flooring compositions) cycloaliphatic polyamines (e.g., isophorone diamine) or low viscosity polyamides can be used.

9

Analysis of Thermoset Materials, Precursors and Products

2.3.4.8 Acid Hardening Systems Acid hydrides are preferred to acids, as the latter release more water during curing which can cause foaming and they are less soluble in the resin. Tertiary amines (e.g., benzyldimethylamine and n-butylamine) are used to catalyse the curing reaction. Examples of anhydrides used include phthalic anhydride, hexahydrophthalic anhydride and, where fire retardancy is required, chlorendic anhydride.

Table 3 Catalysts for polyurethane products Catalyst

Product

Methylene-bis-dimethyl- Flexible foams and potting cyclohexylamine compounds N,N’-Dimethylbenzylamine

Semi-rigid foams and prepolymers

Dibutyltin dilaurate

Reaction injection moulding (RIM) products and two part moulding systems

Ferric acetylacetone

Cast elastomers based on TDI

2.3.4.9 Miscellaneous Systems In this group are amides that include amine groups, dicyanodiamide (used in epoxy adhesives), and complexes of boron and amines such as monoethylamine.

2.3.4.10 Polyurethanes The versatility of polyurethanes is illustrated by the range of catalysts that are used in production of the various products. Some examples are given in Table 3.

2.3.4.11 Acrylic Adhesives (Table 4)

Table 4 Curing systems for acrylics Product

Curing system

Elevated temperature cure methyl methacrylate

Peroxide crosslinking agent

Ambient temperature cure methyl methacrylate

Peroxide crosslinking + amine promoter

Anaerobic acrylic adhesives (e.g., tetramethylene glycol dimethacrylate)

Peroxide crosslinking agent + amine promoter

Cyanoacrylates

Weak base such as water to induce anionic polymerisation

2.3.4.12 Acrylic Thermosetting Resins Peroxides are used to crosslink acrylic resins via the carbon-carbon double bonds present in the low molecular weight precursors. These types of resin are used for laminating.

2.3.5 Flame Retardants Although some thermoset polymers have very good inherent fire retardant properties (e.g., furan and silicone resins), it is often necessary to add fire retardancy into a thermoset product. One or more of the original reactants can be inherently fire retardant and this will then impart this property to the final product. It is also possible to use a number of additives to provide a measure of fire resistance. Examples include organic compounds such as chlorinated phosphate esters and melamine. Inorganic compounds which can be used include hydrated alumina and zinc borate.

10

2.3.6 Lubricants Various lubricants can be used in the manufacture of phenolic products. For example, stearic acid and metal stearates such as calcium stearates can be used at levels in the 1-3% w/w region. It is also possible to use other substances such as carnauba, ceresin and oils such as castor oil. In addition to zinc, magnesium and aluminium stearate, oxidised paraffin wax and sulfonated castor oil have been used as lubricants in urea-formaldehyde resins.

2.3.7 Miscellaneous Additives A number of other types of additives can be used in thermoset products including blowing agents (e.g., hydrochlorofluorocarbons) for foam production,

Analysis of Thermoset Materials, Precursors and Products

pigments (e.g., carbon black and numerous organic and organometallic types) and surfactants (e.g., organosiloxanes) to stabilise gas bubbles in foam manufacture.

and diamines) are trapped in a cold trap and then analysed by gas chromatography. The monomer and hence polymer type can be obtained from the identity of these species. End group analysis is used to characterise the reactive intermediates of certain thermosets. For example:

3 Overview of Analytical Techniques 1. Isocyanate groups in polyurethane prepolymers (ASTM D 2572)

3.1 Wet Chemistry Techniques Before the advent of modern instrumental techniques, analysts relied on a sequence of wet chemistry reactions to determine information such as the generic polymer type of a material. The amount of wet chemistry carried out in the modern polymer analysis laboratory in the 21st Century is minimal. There are some tests which can still be grouped under this heading, although even some of these can employ an instrumental technique to provide the final answer. There are certain functional group tests that are useful for thermosets. Examples include:

2. Hydroxyl groups in polyurethane polyols (ASTM D 4274) 3. Silanol groups in silicone systems can be determined by the Karl Fischer technique (a.13). Silanol groups react with the methanol in the Fischer reagent and one molecule of water is produced per SiOH group. The water formed reacts with the Fischer reagent and the excess reagent is then determined. 4. Hydroxyl groups in epoxy resins have been determined using lithium aluminium hydride (a.14).

2. Ester groups in alkyd and polyester resins can be determined by saponification in alcoholic potassium hydroxide (a.9-a.11).

Wet chemistry methods can also be employed to obtain the extent of reaction (i.e., molecular weight) and purity data on thermoset systems. One of the best examples of this is the standard EN ISO 11402 (1998) standard to determine free formaldehyde in condensation resins. This standard brings together three wet chemistry methods that can be used for this type of determination. The choice of procedure to be used is made according to Table 5 (see also Standards in Table 1).

Schleuter and Siggia (401) and Frankoski and Siggia (a.12) have used the technique of alkali fusion reaction gas chromatography for the analysis of imide monomers and aromatic polyimides. The sample is hydrolysed with a molten potassium hydroxide reagent at an elevated temperature in a flowing inert atmosphere. The volatile reaction products (amines

The standard defines free formaldehyde as ‘formaldehyde that is present in the unbound form as formaldehyde, formaldehyde dihydrate (dihydroxymethylene) or polyoxymethylene’. Formaldehyde receives a lot of attention in these types of products due to its relatively high toxicity as well as its technological significance.

1. Epoxy groups in epoxy resins can be determined by spectrophotometric titration with a halogen acid and spectrophotometrically using 2,4dinitrobenzene sulfonate as the chromophore (a.8).

Table 5 Procedures to determine free formaldehyde in resins Procedure

Suitable for the following thermosets

Hydroxylammonium chloride procedure (ISO 9397)

Phenolic resins, furan resins (unmodified with urea or melamine resin)

Sulfite procedure (ISO 9020)

Urea resins, melamine resins, furan resins, urea-melamine resins, furan-urea resins

Potassium cyanide procedure (ISO 11402)

Melamine-phenolic resins, urea-phenolic resins, urea-melaminephenolic resins

11

Analysis of Thermoset Materials, Precursors and Products

Another standard which uses a wet chemistry approach to determine formaldehyde is BS 2782 (see Table 1). This standard applies to phenolic moulding products only but also encompasses the determination of sulfates and chlorides in such products.

3.2 Spectroscopic Techniques 3.2.1 Infrared Spectroscopy (IR) Infrared spectroscopy (IR) is used extensively in the analysis of thermosets. It is a very good, relatively quick technique for the determination of the polymer present in a thermoset product. It is normally possible to record infrared spectra directly on the cured sample using either a surface technique (e.g., attenuated total reflectance spectroscopy (ATR)) or in transmission through a thin section. In the case of the product precursors, infrared data can be obtained by transmission through a film. Where the thermoset contains a low molecular weight organic modifier, it will need to be extracted with a solvent (e.g., methanol) to clean it up, and products that are filled (e.g., glass filled polyester resins) will require a pyrolysis technique where a pyrolysis condensates infrared library, such as the one published by Rapra Technology, needs to be available (152). The analysis of a solvent extract obtained to prepare the thermoset sample for an IR technique can be used to identify the organic modifier present in the compound, and an IR analysis of an ash of the compound obtained by heating at 550 °C can help to identify inorganic fillers. IR can also be used to identify specialist additives such as fire retardants. The infrared microscope can be used to obtain infrared spectra on fibrous fillers, to identify the type, and it can also be used to obtain spectra on contaminants within starting materials and finished products to enable their origin to be traced.

3.2.2 Ultraviolet Light Spectroscopy (UV) Although not as universally used as IR, UV is another spectroscopic technique which has a role to play in the analysis of thermosets. It is used in the qualitative and quantitative analysis of additives, particularly antioxidants and UV stabilisers.

12

3.2.3 Nuclear Magnetic Resonance Spectroscopy (NMR) NMR is a powerful tool for the determination of polymer structure. It is at its most sensitive when used on analytes in solution. It is commonly used to characterise the reactive precursors of thermosets in studies that relate the structure of these intermediates to the properties of the final product. Of the conventional instruments, both proton and carbon-13 instruments have been used in plastics analysis. It is possible to use solid state NMR for the thermoset products, but the sensitivity is limited and it is difficult to obtain structural information on entities representative of 10% or less of the whole.

3.2.4 Atomic Absorption Spectroscopy (AAS) This technique, and the related inductively coupled plasma (ICP), are used where it is necessary to quantify metals in a thermoset. It can be useful in the identification of certain pigments and fillers.

3.2.5 X-Ray Fluorescence Spectroscopy (XRF) This technique is very useful for obtaining semiquantitative elemental data from thermoset products and their ashes. Among other things, it helps to identify inorganic fillers and pigments in samples. The technique is usually used in conjunction with IR. When it comes to analysing small samples, sample surfaces or contaminants in samples, the scanning electron microscope (SEM)/XRF combination (sometimes referred to as energy dispersive analysis (Edax)) can be a very valuable tool.

3.2.6 Raman Spectroscopy Until 1986 Raman spectrometers were either dispersive long focal length double monochromators or shorter focal length triple monochromators and required highly trained scientists to obtain good quality data. The advent of the Fourier Transform (FT)-Raman technique in 1986 significantly reduced data acquisition times and also brought the technical advantage of suppressing any laser induced fluorescence within the sample (388). Further developments have enabled smaller, low cost, high performance, quality instruments to be produced and

Analysis of Thermoset Materials, Precursors and Products

have led to the development of the Raman microscope – an instrument analogous to the IR microscope. This has enabled Raman spectroscopy to be used routinely for the identification of polymer types and the analysis of contaminants within polymer samples (70).

stable to be analysed by GC or GC-MS. This is particularly the case with antioxidants such as Irganox 1010 and 1036. HPLC also comes into its own in the quantification of relatively high molecular weight organic additives, e.g., oils.

3.3 Chromatographic Techniques 3.3.1 Gas Chromatography-Mass Spectrometry (GC-MS) This powerful, versatile technique can be used to obtain a significant amount of compositional information on thermoset samples. It is particularly useful in identifying minor components of the sample such as the stabiliser, antistatic agent and, where appropriate, crosslinking system. It can also be used to investigate the polymer fraction within a sample when the instrument is fitted with a pyrolysis unit set at around 600 °C. The technique also plays a role in failure diagnosis by being able to provide information on odours, and organic contaminants that may have degraded the thermoset matrix. There are a variety of ways that the sample or fractions of the sample (e.g., an extract) can be analysed by GCMS. These include static headspace, dynamic headspace, solution injection and pyrolysis.

3.3.2 Gas Chromatography (GC) This technique can also be used to obtain polymer type information by use of a pyrolysis approach, although the technique is less powerful because of the absence of a mass spectrometer. A pyrogram ‘fingerprint’ has to be used and a comparison made against a library of known standards. The technique is also used for the identification and quantification of additives such as antioxidants, although care has to be taken as retention time data alone is used in the identification step.

3.3.3 High Performance Liquid Chromatography (HPLC) HPLC can be used to identify and quantify additives that are either too involatile or insufficiently thermally

3.3.4 Liquid Chromatography-Mass Spectroscopy (LC-MS) This instrument is essentially a coupling of an HPLC with a mass selective detector and as such offers a significant enhancement in performance to the polymer chemist. Although such combinations have been around for many years, they were complex and expensive (i.e., effectively research tools only), and it is only within the last five years or so that single quadrupole bench top LC-MS systems have become reasonably common place due to their relative ease of use and cost. A mass spectrometer can be the ideal detector for liquid chromatography because it offers both universality and the required selectivity for complex analytical problems. For many years development work has concentrated particular on the design of the interface between the chromatograph and detector. Today, the two most popular types of interface for the bench top single quadrupole LC-MS are the particle beam interface and the atmospheric pressure ionisation (API) interface. The particle beam interface is used to generate electron ionisation (EI) spectra and the API interface is used to generate either electrospray (ESI) or atmospheric pressure chemical ionisation (APCI) spectra. A further complexity is that the API interface can generate either positive (i.e., molecular ion plus one hydrogen) spectra or negative (i.e., molecular ion minus one hydrogen) spectra. The particle beam interface is very good for qualitative work because the 70 eV spectra contain a significant amount of structural information and can be searched against conventional mass spectra libraries. However, in the full scan mode the sensitivity is restricted to the low nanogram levels. In the case of the API interface, both the electrospray and APCI modes are soft ionisation techniques which leave the molecular ion (or pseudomolecular ion) intact without much fragmentation. The interface therefore offers more sensitivity and is ideal for quantitative work at low levels (e.g., contamination of drug and food matrices by polymer additives/breakdown products).

13

Analysis of Thermoset Materials, Precursors and Products

3.3.5 Gel Permeation Chromatography (GPC) For this technique to be successful the sample must be readily soluble in an organic solvent. This technique has been used extensively in the characterisation of precursor mixtures, for example novolacs used in the production of phenolic resins. Using a low molecular weight column set, the technique can identify the number of oligomers present and the relative quantities. In the case of some complex thermoset systems, the development of interfaces such as the Lab Connections LC Transform, have proved very useful in increasing the amount of information that can be obtained in a GPC analysis by enabling IR data to be recorded on the resultant chromatogram. Hence, with the correct choice of separating column, mixtures of reactive precursors, or blends of organic additives isolated from a thermoset matrix, can be separated and identified.

3.3.6 Thin Layer Chromatography (TLC) TLC is a relatively simple technique that can be used for both the separation and identification of additives such as antioxidants and UV stabilisers. A number of approaches are possible using different developing solvents and spraying agents. It is also the case that TLC can be used in a preparative way for the isolation of sample fractions for subsequent chromatographic or spectroscopic analysis. TLC does have the image of being somewhat old fashioned and it is to be expected that the market penetration of LC-MS systems will further erode the standing of this technique in the modern analytical laboratory.

3.3.7 Supercritical Fluid Chromatography (SFC) SFC has been in use as a separation tool since the early 1960s. The principle behind it is that above its critical point a substance has a density and solvating power approaching that of a liquid but its viscosity is similar to that of a gas. Its diffusivity is intermediate between those of a gas and a liquid. These properties make supercritical fluids very useful as chromatographic mobile phases because they offer the following advantages: a) Extraction and solvation effects allow the migration of materials of high molecular weight

14

b) The high diffusivity confers very useful mass transfer properties, so that higher efficiencies in shorter analysis times are possible than are achieved with HPLC c) The low viscosity means that the pressure drop across the column is greatly reduced for a given flow rate d) The density of the supercritical fluid and, hence the solubility and retention of different compounds, can be easily varied by changing the applied pressure In addition to these advantages, SFC has the advantage over GC in that it can be used to analyse compounds that are thermally labile or non-volatile, and the advantage over conventional HPLC for the analysis of certain species because it can be used with a sensitive universal detector such as a flame ionisation detector (FID). The advent, though, of relatively cheap LC-MS systems has enabled HPLC to counter this advantage to a degree. SFC systems have been used successfully to characterise the precursors of a number of thermosetting systems.

3.4 Thermal Techniques 3.4.1 Differential Scanning Calorimetry (DSC) DSC is a useful tool for studying the curing of thermosets via the heat capacity change that occurs – an exotherm resulting, the intensity of which can be measured in j/g of material. Although not as sensitive as DMTA to glass transitions, DSC can also be used to identify the glass transition of thermosets. It is also possible to use DSC to provide quality control fingerprint thermograms from which deviations in the composition of a thermoset compound can be detected. DSC can also be used in thermal stability studies of a thermoset product and to investigate the effectiveness of antidegradants and fire retardants.

3.4.2 Dynamic Mechanical Thermal Analysis (DMTA) DMTA is very useful for generating modulus versus temperature data on thermoset compounds. The

Analysis of Thermoset Materials, Precursors and Products

effects of temperature on this important material property can be obtained over a wide temperature range (typically –150 to +200 °C), along with the glass transition temperature and information on thermal stability. The sensitivity of DMTA to glass transition temperatures (Tgs) (approximately 1000 times greater than DSC which measures heat capacity changes rather than modulus) is very useful in the analysis of thermosets and their oligomeric precursors. The DMTA can also be used to investigate the effect of loading on thermoset materials (i.e., creep tests). Because, in common with rubbers and plastics, thermoset materials are viscoelastic in nature, behaviour under load is time as well as temperature dependent. A constant load exerted for a prolonged period of time will produce a decline in modulus in the same way as an increase in temperature will. By using the DMTA to apply stress for a given duration (e.g., 30 minutes) at a number of given temperatures (e.g., 6) it is possible to use the time-temperature superpositioning to produce a master curve of the modulus at a given temperature over an extended period (e.g., days). This type of work can be carried out on materials such as glass reinforced polyesters, impact modified phenolics and epoxy resins. A feature of the data generated is that although there is a relatively minor change in modulus resulting from an increase in test temperature below the material’s Tg, the time related effects become more significant and occur over shorter periods of time as the reference temperature approaches this Tg.

3.4.4 Thermogravimetric Analysis (TGA) This technique is useful in the analysis of compounded thermoset samples. It is possible to obtain accurate quantifications of the principal compound constituents such as solvents/organic modifiers, polymer, inorganic fillers and glass fibres. It is also possible to quantify functional additives such as graphite and carbon fibres. This data can be obtained on small (e.g., 10 mg) samples in a relatively short time (around 45 minutes). By the use of the temperature maxima at which weight events occur it is also possible to use the technique to obtain some qualitative assignments for the polymer type. The following describes a typical TGA programme. Heat from ambient to 550 °C in a nitrogen atmosphere at 20 °C/min until no further weight loss occurs. Then, reduce the heat to 300 °C, change the atmosphere to air and heat at 20 °C/min to 1000 °C. It is usually common to plot the weight loss derivative in conjunction with the weight loss to assist in the interpretation of the trace. Figure 1 shows the TGA trace of a melamineformaldehyde product that has been produced using the above programme. Other uses for the technique include the production of compositional fingerprints for quality control purposes and the investigation of thermal stability and the effects that additives such as flame retardants and antioxidants have on it. It is possible to interface modern TGA instruments directly to IR instruments or mass spectrometers, thus obtaining both quantitative and qualitative data in one analytical step

3.4.3 Thermal Mechanical Analysis (TMA) TMA is essentially the static version of DMTA. It has the ability to measure linear or volumetric changes in the dimensions of polymer materials. The data obtained provides valuable information on a range of properties including coefficient of thermal expansion, viscosity, gel time and temperature, glass transition temperature, modulus and the creep/stress relation. As with DMTA, the technique is capable of being used over a wide temperature range (e.g., –150 to >200 °C). It is often encountered in instruments that can apply more than one thermal technique simultaneously to a sample. For example, the microTA instrument from TA instruments which is a combination of TMA and DMTA, and instruments that combine TMA with TGA.

3.4.5 Dielectric Analysis (DEA) Dielectric analysis measures the two fundamental electrical characteristics of a material (capacitance and conductance) as a function of time, temperature and frequency. The capacitive nature of a material reflects its ability to store an electrical charge while the conductive nature is the ability to transfer an electrical charge. While these properties are important in themselves, they have more significance when they are related to changes in the molecular and/or structural state of a material. The actual parameters monitored using dielectric analysis are e′ (permittivity), which is a measure of the degree of alignment of the molecular dipoles in a material, and e′′ (loss factor), which represents the energy required to align the dipoles or to move trace ions.

15

Analysis of Thermoset Materials, Precursors and Products

Figure 1 TGA trace of a melamine-formaldehyde sample

Dielectric analysis can be used to study the curing behaviour of thermosets such as phenolic resins. It has the advantage over DSC in that it is not affected by the evolution of volatiles or the dilution of the polymer fraction by fillers such as fibre glass. Compared to DMTA, it has the advantage of being able to be used with pellets, powders or liquids. The technique is capable of being used over a wide frequency range (from 3 mHz to 100 KHz) and this enables the analyst to study the material's behaviour

over a very large range. Low frequencies (those below 30 Hz) provide a sensitive means of studying the cure in the thermosetting resin. DEA is also one of the most sensitive thermal techniques for the determination of Tg. The relative sensitivity of a technique for this type of work depends on the degree of change in the measured parameter as the material passes through its Tg. A comparison of the principal thermal techniques is given in Table 6.

Table 6 Comparison of the relative sensitivity to Tg of thermal analysis techniques Technique

Measured parameter

Relative sensitivity*

DSC

Heat capacity

1

TMA

Coefficient of expansion

5

Modulus (damping modulus)

10

Permittivity (loss factor)

10

DMTA DEA *10 represents the most sensitive

16

Analysis of Thermoset Materials, Precursors and Products

3.5 Elemental Techniques The determination of the concentration of certain elements can be very useful. In particular, it is often necessary to determine the amount of a particular metal or element to enable the quantity of a certain additive (e.g., filler, pigment or catalyst) to be calculated. One of the prime techniques for this type of work (AAS/ICP) has already been covered (Section 2.2.4). The determination of carbon, hydrogen and nitrogen can be useful for determining the amount of major constituents such as base polymers and is usually done using carbon/hydrogen/nitrogen (CHN) analysers. The technique is relatively simple and uses small amounts (e.g., 20-50 mg) of sample. With the other elements, the technique will vary according to the element being quantified. Sulfur and chlorine for example can be determined using oxygen combustion followed by ion chromatography analysis of the products.

report. These include X-ray diffraction (XRD) to identify different crystalline forms of inorganic additives (e.g., rutile and anatase forms of titanium dioxide) and direct probe mass spectroscopy, for the determination of high molecular weight antioxidants. Surface analysis techniques such as secondary ion mass spectrometry (SIMS), laser induced mass analysis (LIMA) and X-ray photoelectron spectroscopy (XPS) are used for failure diagnosis work associated with such things as poor bonding to substrates and for surface characterisation work. Moisture in thermoset resins can cause difficulties such as mould flow problems, blistering or a decrease in hot strength. There are instruments on the market that can routinely measure the moisture content of samples such as epoxy resin moulding powders down to ppm levels. Two such instruments are the Karl Fischer apparatus and the TA Instruments 903 Moisture Evolution Analyser.

3.6 Microscopy Techniques

4 Characterisation of Thermoset Polymers and their Precursors

High magnification (e.g., 150 x) optical microscopy can be used to examine the dispersion of fillers and fibres within the sample matrix. The success of this operation is usually dependant on the generation of high quality microtome sections of the sample.

4.1 Determination of the Molecular Weight of Thermoset Precursors and the Separation of their Oligomers

The technique of scanning electron microscopy has already been briefly mentioned in Section 3.2.5 in relation to the elemental analysis of surfaces in conjunction with XRF. It can also be used in its own right, where its high magnification powers can be employed to determine the particle size of fillers and in the detailed examination of fracture surfaces.

By their nature, thermoset materials are three dimensional systems and so have an infinite molecular weight. This type of characterisation technique is therefore confined to the analysis of the various oligomeric and relatively low molecular weight precursors that are used to manufacture certain of these polymers. Important examples include the polyurethane prepolymers and novolac resins for the manufacture of phenolic resins.

Transmission electron microscopy (TEM) can be used in investigate the phase morphology of samples and the dispersion of fillers.

There are a number of ways in which the molecular weight distribution of a prepolymer can be expressed:

The IR microscope and Raman microscope are covered in the relevant spectroscopy sections.

Mn = Number average molecular weight = Sum nM Sum n Mw = Weight average molecular weight = Sum nM2 Sum nM

3.7 Miscellaneous Techniques Mz = Z average molecular weight There are a number of other analytical techniques that can be used to characterise thermoset samples and many of these feature in the abstracts at the back of this review

= Sum nM3 Sum nM2

Where n = the number of molecules of molar mass M

17

Analysis of Thermoset Materials, Precursors and Products

polar solvent (e.g., hexafluoroisopropanol (HFIP)) be used as the eluent and an elevated temperature be used. In others, the more ‘standard’ conditions of THF as the eluent and an ambient operating temperature will suffice.

The Z average is very sensitive to high molecular weight molecules within the prepolymer. The weight average is always of greater value than the number average and a measure of the breadth of the molecular distribution of the prepolymer can be obtained by dividing the weight average by the number average:

Table 7 shows some typical GPC eluents and operating temperatures for a range of thermoset precursors.

Polydispersity = Mw Mn

The standard detector for GPC systems is the refractive index (RI) detector, but a feature of developments over the past 10 years is the development of double (RI and viscosity) or triple detector systems (RI, viscosity and light scattering). These multiple detection systems provide measures of ‘true’ molecular weight by obtaining actual Mark-Houwink parameters (in the case of the viscosity detector) for the polymer being analysed, as opposed to polystyrene equivalent molecular weight from the use of monodisperse polystyrene calibrants alone. An inherent property of the light scattering detector is that it provides ‘true’ molecular weight data.

As the prepolymer tends to monodispersity the polydispersity approaches unity. Although there are potentially a wide variety of methods that can be used to obtain molecular weights, the most common method for prepolymers is gel permeation chromatography (GPC).

4.1.1 Gel Permeation Chromatography This technique which was originally developed to characterise high polymers such as plastics and rubbers, has been refined and developed extensively over the past 30 years.

GPC coupled with multi-angle laser light scattering detection has been used by Podzimek and Hyrsl (297) to characterise unsaturated polyester resins. Using a number of examples, the results obtained are compared to those produced by conventional GPC with refractive index detection.

It can be used to obtain Mn, Mw and Mz values. GPC is essentially a liquid chromatography technique where the sample is dissolved in a suitable solvent (e.g., tetrahydrofuran (THF) for polyurethane prepolymer) and injected into a system where the molecules are separated according to their molecular size by a column that contains a swollen, particulate, porous gel packing.

The use of the LC transform module with GPC has extended its capabilities by allowing IR data to be generated on the species during the course of an analysis. This is done by impinging the species onto a germanium disc which is then placed into a module fitted into the sample compartment of an IR bench. IR

In some cases, for example melamine-formaldehyde resins, the polar nature of the material requires that a

Table 7 GPC eluents and operating temperatures for thermoset precursors Solvent

Temperature (°C)

Alkyds

THF

ambient

Epoxies

THF

ambient

Melamine resins

HFIP

40

Phenolic resins

THF

ambient

Toluene Chloroform

80 ambient

THF Dimethylformamide (DMF)

ambient 80

HFIP

40

Polymer

Silicones Polyurethanes Urea resins

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Analysis of Thermoset Materials, Precursors and Products

data is collected on the entire chromatogram using continuous collection software, which enables the IR spectrum of any particular section to be viewed. This technique is very useful for systems where more than one chemical type is present, either due to the presence of organic modifiers or a blend of oligomers.

G2000H8 with both refractive index and UV detection. Tetrahydrofuran was employed as the eluent at a relatively low flow rate of 0.5 ml/min. The masses of the seven separated species ranged from 1614 to 220.

It is also possible to use an infrared detector with GPC. Birley and Blinkhorn (392) used a GPC system fitted with an infrared detector to study phenolformaldehyde prepolymers (novolacs). The separations were studied by monitoring the phenolic hydroxy group at 3400 cm. A number of other workers have also used GPC to study novolacs. Hasegawa and co-workers (396) characterised two kinds of novolac having different ortho-/para-ratios for methylene linkages using polystyrene type packings and found that it was necessary to add lithium bromide modifier to the DMF eluent to eliminate unexpected chromatographic effects. The molecular weight characteristics of novolacs made from the reaction of phenol or p-cresol with formaldehyde in various mole ratios were studied using both GPC and vapour phase osmometry (349). The results revealed a relationship between the content of residual dihydroxydiphenylmethane and the number average molecular weight of the resulting novolac.

4.1.2 Liquid Chromatography Techniques

Figure 2 shows the GPC separations that have been obtained on two different low molecular weight phenolformaldehyde systems – a resol and a novolac. In addition to obtaining molecular weight distribution data on prepolymers, GPC can also be used to perform oligomer separations. In this case high resolution columns are used that contain packings having small pore sizes (e.g., 50 Å). It can sometimes be necessary to increase the effective resolving power of the system by using a number of columns coupled together or using a recycle valve to effectively increase the bed length. In this way the number, molecular weight and relative abundance of the individual, separated oligomers can be obtained. Calibration of these types of system is performed using oligomeric standards such as the polystyrene 580 available from Polymer Laboratories. Care has to be taken as the behaviour of the oligomers can depart from a true size exclusion mechanism at such low molecular weights, and the hydrostatic volumes of the molecules in solution become more important than at higher molecular weights. Krishen (a.15) separated nonylphenol-formaldehyde adducts using a 610 mm column of TSK-gel

Comparisons have been made between the abilities of GPC and HPLC to perform oligomer separations on thermoset prepolymers. Van der Maeden and coworkers (a.16) analysed both a novolac and an epoxy resin mixture and achieved the separation of sixteen discreet species in each case. The HPLC separations were achieved with gradient elution on a reversed phase μ-Bondapak C18 column. However, the HPLC separations took longer than GPC and the reversephase eluent had to be varied for the two polymer types. Kuo and co-workers (a.17) used the two techniques to separate polyester oligomers and other low molecular weight precursors used in the coatings industry. Other occasions where GPC has been used to separate oligomers include two examples where polyester oligomers have been characterised by Shiono (400) and by Zaborsky (a.18). Another example of HPLC being used to separate oligomers is given by Ludwig and Bailie (a.19) who used it with a normal phase silica type column to characterise p-alkylphenyl formaldehyde oligomers. Kuo and co-workers (156) used both GPC and HPLC for the characterisation of coatings systems which used low molecular weight polymers, oligomers and reactive additives to produce high molecular weight, crosslinked films. Another liquid chromatography technique which has been used to characterise thermoset oligomers is supercritical fluid chromatography (SFC). The high dissolution power of supercritical fluids for some low molecular weight polymers and the high efficiencies of capillary columns make SFC particularly suitable for oligomer separations. The resolution that can be obtained is higher than that with GPC, and thermally unstable species (e.g., polyglycols) do not require a derivatisation step as the analysis temperature is below their decomposition temperature. In some cases, for example polydimethyl siloxanes, the resolution is sufficiently high to separate oligomers by chain

19

Analysis of Thermoset Materials, Precursors and Products

Figure 2 Separation of (a) resol and (b) novolac phenol-formaldehyde oligomers by GPC

length as well as degree of branching for a given oligomer size. The use of the technique on a large number of polymers has been reported (a.20), including methylphenylsiloxanes, polyesters, epoxies and isocyanates. In the case of epoxy acrylate oligomers, a 20 m x 50 μm i.d. SB-biphenyl100 column was used with a carbon dioxide supercritical mobile phase at an isothermal temperature of 70 °C. Linear density programming was used with an FID detector.

20

4.1.3 Epoxy Resins The epoxy resins used in pre-pregs (fibre reinforcement pre-impregnated with partially cured resin) have been characterised by Noel and co-workers (a.21). The separations were carried out using a 5 μm, 100 Å GPC column with THF as the eluent. The samples were prepared by extracting the pre-pregs with THF three times, each time for 15 minutes, and combining the extracts. It was possible to detect monomers such as

Analysis of Thermoset Materials, Precursors and Products

diaminodiphenylsulfone and tetraglycidyldiamino diphenylmethane in the extracts. The effect of ageing, which results in polymerisation and an increase in the high molecular weight components, was also studied. The peak corresponding to the amine hardener was also useful in monitoring the onset of ageing. Figure 3 shows the use of GPC to obtain comparative molecular weight data on three different epoxy prepreg systems and Figure 4 shows the molecular weight distribution of an uncured epoxy resin analysed using the conditions: Columns

2 x PL gel mixed bed-B, 30 cm, 10 μm packing

Solvent

THF

Flow rate

1.0 ml/min

Temperature

30 °C

Detection

Refractive index

Solution concentration 2 mg/ml Ishiguro and co-workers (a.22) have also used GPC to separate the oligomers present in a commercially available epoxy resin (Epikote 1001). Resolution of the sample into fourteen epoxy oligomers was achieved on two sets of four 30 cm long columns in series having exclusion limits of 5 x 10 3 and 2 x 10 4 g mol -1, respectively.

4.1.4 Polyurethane Work has also been carried out on polyurethane intermediates. The identification of oligomers in the reaction of polyols with isocyanates has been carried out by Sebenik and co-workers (393) using GPC in conjunction with 13C NMR. The results enabled kinetic and mechanism schemes to be derived for the reaction. Noel and Van Gheluwe (a.23) have analysed a polyether polyol intermediate by GPC and were able to quantitatively determine the oligomers present.

has been shown to give better resolution of oligomers than a conventional 1 m x 8 mm column. Mori (a.24a.26) has used microbore-GPC to study the oligomers of epoxy resin, phenol-formaldehyde and methylated melamine-formaldehyde resins.

4.1.6 Other Techniques Other techniques which are used to obtain molecular weight data and have a limited applicability to thermoset precursors include:

4.1.6.1 Viscosity This procedure involves the use of specially designed viscometers to accurately measure the viscosity of the polymer solution. From this the intrinsic viscosity is determined and hence the molecular weight. The time taken for the polymer solution to pass between two marks on the viscometer is compared to that of pure solvent and the ratio is the viscosity of the solution. Successive dilutions give a range of concentrations and times from which the intrinsic viscosity can be calculated. The value for this is then entered into the Mark-Houwink equation: Intrinsic viscosity = KMX where K and X are constants for the particular solvent being used and are referred to as the Mark-Houwink parameters. Depending on the source of the Mark-Houwink parameters the molecular weight can be expressed as either the number or weight average. A number of molecular weight characterisation techniques, including intrinsic viscosity, have been used by Kim and co-workers (381) to study a phenolformaldehyde wood adhesive resol resin synthesised by sodium hydroxide catalysts.

4.1.5 Microbore-GPC 4.1.6.2 Osmometry Over the years there has been some interest in the technique of microbore-GPC, where narrow bore columns are employed. The columns are packed with conventional gels but have very small internal diameters (e.g., 0.35 mm). With a number of these columns connected in series very high separation efficiencies can be achieved and a 2 m x 0.35 mm combination column

There are two principal osmometry techniques: vapour pressure osmometry and membrane osmometry. Vapour pressure osmometry involves the indirect measuring of the lowering of the vapour pressure of a solvent due to the presence of a solute. It is based

21

Analysis of Thermoset Materials, Precursors and Products

Figure 3 Molecular weight comparison of three epoxy pre-pregs by GPC

Figure 4 Molecular weight distribution of an uncured epoxy resin as determined by GPC

22

Analysis of Thermoset Materials, Precursors and Products

on the measurement of the temperature difference between droplets of pure solvent and of polymer solution maintained in an isothermal atmosphere saturated with the solvent vapour. Calibration is by the analysis of standards of known molecular weight and should be over the entire molecular weight of interest to ensure the best results. The technique is useful for polymers/oligomers that have molecular weights in the 500-50,000 range.

single bounce attenuated total reflectance (ATR) accessories (e.g., the ‘Golden Gate’) for FTIR instruments enables this operation to be carried out in a matter of minutes on a sample a couple of millimetres in size. Some care should be taken as the relative intensities of the bands present in ATR spectra can vary compared to conventional transmission spectra (historically used to compile databases) and there is a slight shifting in the absorption wavenumber value of the bands.

4.2 Polymer Type and Microstructure

Figure 5 shows the single bounce ‘Golden Gate’ ATR spectrum of a melamine-formaldehyde sample. Figure 6 shows the transmission infrared spectrum of an uncured phenol-formaldehyde moulding material cast from a solution in THF.

4.2.1 Infrared Spectroscopy One of the most basic tests to perform on a thermoset material is to determine its generic polymer type and there are a number of different approaches based on infrared spectroscopy (IR) to achieve this depending upon the sample’s complexity. If the sample is not heavily modified with additives, it is usually possible to carry out an infrared analysis of it in the as received state and obtain an identification by reference to a standards database. The advent of the

For those thermoset compounds that contain a plasticiser and/or organic flame retardant, a certain amount of preparation work is required to effectively remove the interference of these constituents. After milling or commuting the sample to increase surface area, a solvent extraction is performed to remove these organic species. It is then usually possible to record the infrared spectrum using an ATR technique.

Figure 5 ‘Golden Gate’ ATR spectrum of a melamine-formaldehyde sample

23

Analysis of Thermoset Materials, Precursors and Products

Figure 6 Transmission infrared spectrum of a phenol-formaldehyde sample

Where the thermoset sample contains both a major organic additive and a filler, it is necessary to pyrolyse the extracted portion of the sample and then record an infrared spectrum of the collected pyrolysis condensates. Providing that an extensive database of pyrolysate spectra is available (e.g., 151), this method is successful in identifying generic polymer types. There can be problems with this technique in differentiating between polymers having similar structures (e.g., phenol-formaldehyde, ureaformaldehyde and melamine-formaldehyde) and in these cases other techniques such as solid state NMR have to be employed. The pyrolysis infrared spectra for samples of melamineformaldehyde, phenol-formaldehyde and a general purpose epoxy resin are shown in Figures 7, 8 and 9, respectively. If the thermoset only contains an inert filler, the pyrolysis approach can be employed without using the initial solvent extraction step. One note of caution with respect to the pyrolysis technique: it is important to record the infrared spectrum shortly (i.e., within 30 minutes) after pyrolysis of the sample

24

as it has been found (a.27) that if the condensates are exposed to the laboratory environment changes in the spectrum will occur due to oxidation reactions and the loss of volatiles. It is therefore best to perform the experiments sequentially and not in batches. Another potential problem with the use of the pyrolysis technique for thermosets such as phenol-formaldehyde moulding powders is that fillers such as wood flour, coconut shell flour, cotton and nylon can be used and these will also pyrolyse along with the polymer fraction in the sample and contaminate the spectrum. Careful examination of the sample to assess if such a filler may be present therefore needs to take place prior to the pyrolysis step. Where appropriate standards are available, it is also possible to use IR to semi-quantify the amounts of reacted components in mixed systems such as cured epoxy-novolacs where both epoxy and phenolformaldehyde structures are present. An example of another complicated system is the modification by epoxy resins of stoving enamels based on acrylic resins or alkyd/melamine resins.

Analysis of Thermoset Materials, Precursors and Products

Figure 7 Pyrolysate infrared spectrum for a melamine-formaldehyde sample

Figure 8 Pyrolysate infrared spectrum for a phenol-formaldehyde sample

25

Analysis of Thermoset Materials, Precursors and Products

Figure 9 Pyrolysate infrared spectrum for a general purpose epoxy resin

Hard epoxy resins of the diglycidyl ether-bisphenol A type are manufactured by the reaction of bisphenol and epichlorohydrin. Peltonen and co-workers (a.28) have described an infrared method for determining epoxy resins and their thermal degradation products in workplace atmospheres. Samples were collected on glass fibre filters and the epoxy components removed with chloroform. The chloroform extract was evaporated to dryness and the residue dissolved in deuterochloroform. If it was suspected that thermal degradation products were present, the initial chloroform extract was washed with 1N sodium hydroxide, then water to remove phenolic products. Deuterochloroform was used instead of chloroform because chloroform has a strong absorption at 1510 cm which interferes with the aromatic absorption from the epoxy resin. The amount of epoxy can be quantified by the use of this 1510 cm absorption band, with pure epoxy resin being used for the calibration curve.

In contrast to IR this information can be obtained without having to analyse standards of known monomer composition; the areas under the diagnostic chemical shifts being used. In the case of the liquid precursors, the analysis can be performed on a solution of the sample. An example of this type of study has been carried out by Tawfik and co-workers in Cairo, where a novel monomer (o-carboxy phthalanilic acid) was reacted with different acids and glycols to produce three different unsaturated polyester resins. Proton NMR spectroscopy and IR were used to characterise the structure of the polyesters. Further characterisation work, using techniques such as TGA, was carried out once these polyesters had been reacted with styrene in the presence of methyl ethyl ketone peroxide (MEKP) and a cobalt naphthenate catalyst. Once thermoset materials have been cured in this way, solution based techniques are obviously inappropriate and in order to obtain NMR data, solid state NMR (i.e., magic angle spinning) has to be employed.

4.2.2 NMR Spectroscopy

Bisphenol A-epichlorohydrin epoxies have been studied using NMR (403). The data obtained provided information on the number of repeat units in the polymer and a set of statistical parameters were

Another technique that is very effective at identifying the monomers present in a thermoset material is NMR.

26

Analysis of Thermoset Materials, Precursors and Products

developed that assisted in choosing the shift values to ratio. The repeat unit values obtained in this way were compared to titrimetric values. The NMR results tended to be lower (around 5-10%) than the wet chemistry results, particularly for the high molecular weight resins, but the effect of interferences could be minimised by the choice of shift areas and the technique has the potential to quantify partially cured products. NMR instruments can also be used to obtain fundamental structural information on polymers such as end group chemistry, branch points and structural isomerism. It is also possible to use IR for the latter example, although some of the isomeric structures have relatively weak absorptions which makes their detection when they are at a low concentration difficult.

4.2.4 Pyrolysis Gas Chromatography Another method which enables the polymer type within a thermoset sample to be identified is pyrolysis gas chromatography. This method can be applied to either the extracted portion of the sample or the sample as received. In the former case any relatively low molecular weight additives elute early on and do not have a significant influence on the pyrogram as a whole. As with pyrolysis IR, a database of standards needs to be put together and then the pyrogram fingerprints of unknowns can be matched. The temperature that the pyrolysis unit is set at, and the design of the unit (e.g., Curie point or microfurnace), will affect the pyrograms produced from a particular sample. Again, it is possible to identify and quantify blends and blend ratios. Typical experimental conditions for pyrolysis GC experiments are as follows:

4.2.3 Identifying Functional Groups Sample weights

0.1-5.0 mg

Chemical probe techniques have been used to determine functional groups in thermosets. For example, oxirane rings in epoxy resins have been determined by ring cleavage with pyridinehydrochloric acid (a.29).

Pyrolysis temperatures 400-800 °C (microfurnace and Curie point)

An NMR method has been developed by L’Ho (a.30) that is capable of both quantifying the hydroxyl groups in a polymer and of determining their type (i.e., primary, secondary or tertiary). The method is based on the reaction of the hydroxyl groups with hexafluoroacetone to form an adduct which is amenable to F19 NMR spectroscopy. The tertiary adducts appear at the high field end of the spectrum followed by the secondary and then the primary. An important advantage of this method over chemical methods, such as chemical titration after an initial acylation step, is that species such as water, acid, amines and amides do not interfere. The method has been used on a number of polymer systems including aromatic polyesters and phenolic resins.

Microfurnace type pyrolyser – specific example using an SGE Pyrojector

Dubiel and co-workers (398) have described methods for determining a number of reactive components in room temperature cured silicones. Total silanol (SiOH) and silane hydrogen (SiH) groups were determined by FTIR using the absorption bands at 3687 cm and 2168 cm, respectively. The tetrapropoxysilane content was determined by gas chromatography and the diphenylmethylsilanol content by GPC using THF as the eluent.

800-1200 °C (platinum filament)

Weight of sample

0.4 mg

Pyrolysis temperature

600 °C

Pyrolysis gas

Helium at 15 psi

GC column

5% Diphenyl siloxane 30 m × 0.25 mm, 1.0 μm film

GC column temperature 2 mins at 50 °C followed by programme 10 °C/min to 280 and then 10 mins at 280 °C GC carrier gas

Helium at 10 psi

GC injector temperature 320 °C Detector

FID at 350 °C

Adding a mass spectrometer into the system, so that the technique becomes pyrolysis GC-MS, further increases the usefulness of the method and the information that can be obtained.

27

Analysis of Thermoset Materials, Precursors and Products

Table 8 Diagnostic pyrolysis species Polymer type

Species

Phenol-formaldehyde

Xylene (major component), phenol, cresol and benzene

Polydimethyl siloxane

Cyclic trimer (major component), cyclic tetramer and higher cyclics

Unsaturated polyester, e.g., maleic acid-phthalic acidpropylene glycol-styrene

Ethane, propionaldehyde, styrene (major), phthalic anhydride (major), benzene, toluene, xylene

Polyurethane, e.g., MDI, ethylene glycol, tetrahydrofuran, propylene glycol, adipic acid polyester, butanediol based product

Carbon dioxide, ethylene, propylene, ethylene oxide, propylene oxide, acetaldehyde, cyclopentanone, ethylene glycol, propylene glycol adipic anhydride, aniline

The principal diagnostic pyrolysis species can be detected in pyrograms of thermosets (Table 8). It can be seen from the above list that certain materials ‘unzip’ to regenerate their monomers whereas others undergo decomposition reactions to generate characteristic breakdown products. In reality, a certain amount of both types of reaction take place for the majority of polymers and it is the one that predominates that determines what the major pyrolysis products will be.

4.2.5 Thermal Analysis Techniques Another approach to identifying a polymer is to use its glass transition temperature. Three commonly available thermal techniques can be used for this type of work – DSC, DMTA and TMA. It is the case, however, that as the amorphous proportion of the sample is reduced by crystallinity, crosslink density or the presence of bulk additives such as fillers, the change in heat capacity through the Tg is reduced and DSC becomes less effective. The latter two of these situations often applies to thermoset systems and so techniques that rely on modulus change are better (i.e., DMTA and TMA). Of these two, DMTA is the best structural probe and this has been demonstrated by O’Neal and co-workers (280) in studies carried out on graphite-epoxy composites. With respect to the quantification of the polymer component within a thermoset compound, the easiest technique to use is TGA. Unfortunately, most thermosets contain heteroatoms (e.g., oxygen and nitrogen) and so these products (e.g., phenolics, polyurethanes, polyesters and epoxies) do not completely pyrolyse during the nitrogen atmosphere region and leave a carbonaceous residue which essentially oxidises to carbon dioxide in the air region. This carbonaceous residue, which may to an extent

28

overlap with any weight loss due to a carbon based filler, such as carbon black or graphite, has to be included in order to obtain an accurate polymer content.

5 Determination of Organic Modifiers and Fillers in Thermoset Products 5.1 Determination of Organic Modifiers Mention has already been made in Section 4.1 of the isolation of organic modifiers such as plasticisers from a thermoset matrix by solvent extraction. Careful choice of solvent is required to ensure that the minimum amount of polymer is removed and that the plasticiser is selectively isolated. Examples of solvents which have been found to be useful for a variety of polymer systems are acetone, diethyl ether and methanol. The extraction is carried out under Soxhlet conditions with the weight of extract being obtained from the weight gain of the conditioned solvent reservoir flask once the solvent has been dried off at 105 °C. Having removed and semi-quantified (due to interferences from extracted oligomers, etc.) the modifier present by extraction it is then possible to obtain an identification by the use of transmission IR. There is an excellent database of plasticisers and process aids available (a.31) which enables identifications to be made. Where the organic modifiers have distinct IR spectra (e.g., phthalates and sulfonamides) it is possible to detect the presence of a blend. If a quantification of the blend composition is required, this can be achieved by an analysis of the solvent extract by HPLC or LC-MS. The TGA technique can usually provide a good quantification of modifier content. Modifiers that have

Analysis of Thermoset Materials, Precursors and Products

higher molecular weights (e.g., so called polymerised plasticisers) can give problems as the weight loss event due to their volatilisation can merge with the pyrolysis weight loss event of the polymer. Problems can also be encountered with low molecular weight modifiers such as the solvents used in inks, paints and coatings. These samples can start to lose weight as soon as they are put into the TGA sample pan and in most cases it is advisable to quantify the volatile fraction by drying to constant weight in an oven and then carrying out the TGA analysis on the dried residue to complete the analysis. Low molecular weight modifiers such as those mentioned above can be identified by use of static or dynamic headspace GC-MS. If a quantification of the various components of a mixed solvent system is required, extracting the matrix with a suitably nonselective solvent (e.g., chlorofom), if the product is cured, or dissolving the sample into the solvent if uncured and carrying out injection GC-MS work using appropriate calibration curves is the best way forward. High molecular weight modifiers such as elastomers can be detected and identified in samples such as epoxy prepregs by a combination of GPC and IR. The pre-preg sample can be dissolved in solvents such as THF and the GPC analysis performed using either refractive index or UV detection (depending on the chemical groups within the rubber modifier). Once the chromatographic conditions have been optimised, the LC Transform interface can be used in place of the detector to collect the chromatogram components and infrared spectra recorded of them for identification purposes.

5.2 Determination of Fillers

the former having a maximum oxidation weight loss around 700 °C and the latter around 550 °C. The fact that a number of rubbers (e.g., halogenated, nitrile and polyurethanes) produce carbonaceous residues during the nitrogen atmosphere region has already been mentioned in Section 4.1, and care must be taken to ensure that these do not affect the quantification of the carbonaceous filler in the air atmosphere region. Use of a high resolution TGA instrument will assist in this as it will improve the separation of the two weight loss events. TGA is also convenient for the quantification of inorganic fillers such as barytes, silica and silicates. The limitation of the technique is that the total inorganic content of the plastic is obtained, with no indication of the relative proportion if a blend of inorganic fillers is present. It is therefore common practice to complement the TGA data with at least a semi-quantitative elemental technique such as XRF in order to obtain qualitative as well as quantitative data. A useful exception to this rule is where the compound contains calcium carbonate (a relatively common diluent filler), in which case the carbonate will undergo quantitative degradation at around 680-700 °C into carbon dioxide and calcium oxide (which remains as a residue). It is therefore possible to quantity the amount of calcium carbonate in the sample from the carbon dioxide weight loss (which will represent 44% of the carbonate by mass) and the remaining quantity of residue will indicate if any other inorganics are present. The other technique commonly used for the quantification and isolation of inorganic materials (both fillers and additives such as glass fibres) is furnace ashing. This method is described in ISO 3451-1 (1997) and a temperature of 500-600 °C is usually used.

5.2.1 Particulate Fillers On some occasions, carbonaceous fillers such as a conducting black (acetylene black) or graphite are added to a plastic to enable it to meet certain conductivity requirements. It is possible to use TGA to quantify these types of fillers. It is also a useful way of differentiating between these materials and conventional carbon black;

Once the ash has been obtained, qualitative information on the inorganic species present can be obtained by IR (liquid paraffin mull technique), XRF or, where the quantification of specific species is required, ICP. Some of the principal diagnostic IR absorption bands for inorganic fillers are shown in Table 9.

Table 9 Diagnostic IR absorption bands for inorganic fillers Inorganic filler

IR absorption band

Silica

Broad band at 950-1330 cm which peaks at 1050-1100 cm

Silicates

Broad band at 850-1300 cm which peaks at 950-1100 cm

Calcium carbonate Barium sulfate

1420, 870 and 710 cm 1080 and 610 cm

29

Analysis of Thermoset Materials, Precursors and Products

5.2.2 Fibrous Fillers In certain applications it is necessary to impart the strength required to a thermoset part by the use of fibrous fillers. The following types are among those used: 1. Glass fibres 2. Carbon fibres 3. Synthetic polymer fibres (e.g., nylon)

characteristic stone cells. The standard against which these stone cells are counted consists of a definite weight of lycopodium, which consists of a definite number of lycopodium spores having good uniformity and, hence, easy identification. The moulding powder is quantitatively extracted with acetone first to remove the resin and then the test carried out on the filler residue. Known mixtures of wood flour and coconut shell flour are used to produce a calibration curve. The test is described in detail by Haslam and co-workers (a.34).

4. Wood flour and coconut flour 5. Cotton It is usually obvious whether a thermoset contains a fibrous filler from either a visual inspection or the use of a relatively low powered optical microscope. Glass fibres can be isolated and gravimetrically determined by ashing at 600 °C in a muffle furnace. Higher temperatures (above 700 °C) can cause problems as the glass will eventually reach its melting point. Confirmation that the fibres are glass can be carried out using an infrared microscope. A quantification of the resin, glass and any inorganic material in thermosets such as polyesters can be carried out by determining the weight loss at 600 °C (percentage weight of resin), carefully washing the residue, reacting with hydrochloric acid and sieving through a 200 mesh sieve to remove the inorganic material from the glass prior to a quantitative drying at 105 °C (percentage weight of glass fibre). The percentage of inorganic material present is then found by subtracting these two values away from 100% (i.e., the original mass of the sample). The IR microscope will also give the cellulose spectrum which is expected for the wood flour type fibres, and be able to detect the type of synthetic fibre (e.g., nylon or polypropylene) used from its characteristic transmission spectrum. A test for the determination of wood flour in phenolic moulding powders is described by Toth (a.32). This test involves the phloroglucinol reaction and is used for qualitative purposes. It is sometimes the case that a mixture of wood flour and coconut shell flour is used in phenolic moulding powders and there is a useful method for estimating the relative amounts of the two. The method is a microscopic one based on a principle originally devised by Wallis (a.33) and is based on the fact that coconut shell flour contains

30

The above procedure works on moulding powders by making use of the solubility of the resin prior to any crosslinking reaction. It is often the case though that it is the moulding itself which is presented for analysis. The following method was devised by Haslam and Hill (a.35) to separate the resin and filler in the mouldings. This method is particularly useful in the case of fillers such as coconut shell flour and wood flour that would be destroyed using the isolation by ashing method described above. The method uses the fact that phenol-formaldehyde ‘dissolves’ in warm 2-naphthol. The sample and the 2-naphthol are heated for 4 hours at 170 °C with constant agitation. At the end of this time the reaction mixture is cooled and washed repeatedly with ethanol until the washings are colourless. The filler remains as a residue which can be analysed by techniques such as optical microscopy and infrared spectroscopy. A similar approach can be used to separate the filler and resin in crosslinked ureaformaldehyde resins. In this case the resin is decomposed using acetic acid. TGA will enable the amount of carbon fibres in a thermoset to be quantified. The oxidation temperature of around 700 °C (instead of the 500600 °C experienced with carbon blacks) will also provide a confirmation of their presence. This technique can also be used to determine and quantify the presence of inorganic fibres, such as glass fibres, in materials such as epoxy pre-pregs. An example of such an analysis is shown in Figure 10. As mentioned above, synthetic polymeric fibres can be identified by the IR microscope once sufficiently isolated or, by use of their melting point, by the hot stage microscope or DSC. In the case of DSC, some quantification data can be obtained from the size of the melting endotherm providing standards are available.

Analysis of Thermoset Materials, Precursors and Products

Figure 10 Use of TGA to quantify the amount of glass fibre in an epoxy-fibreglass pre-preg

6 Determination of Functional Additives in Thermoset Products 6.1 Antidegradants Unlike other polymer systems, where this type of additive is essential, the inherent stability of most thermosets means that they do not need an antidegradant to maintain their physical properties and guard against degradation by agencies such as heat and UV light. Where such additives are present, the use of an initial solvent extraction step is common, as these species may not be volatile enough to be removed by heating the sample. In some cases (e.g., butylated hydroxy toluene) heating a sample liberates enough of the species to enable an identification to be made using GC-MS; however quantification will usually require removal by a solvent (to as near 100% efficiency as possible). Analysis of the extract can then be carried out by HPLC, UV spectroscopy, or GC if the species is thermally stable and sufficiently volatile. Relatively non-specific solvents (i.e., having midrange solubility parameters) such as chloroform and diethyl ether are good extracting solvents. If the type of organic antidegradant in a compound is completely unknown, analysis of the solvent extract by GC-MS or LC-MS is an excellent method for identification. Once the identification has been achieved, a quantification can be carried out using a preferred method and a validated procedure if available.

Where the antidegradant is not volatile enough to be identified using a GC based technique, direct probe mass spectrometry or LC-MS can be used and the antidegradant identified by reference to its molecular ion and a database. The direct probe mass spectroscopy technique can be carried out on samples in the as received state as well as sample extracts, whereas LCMS is only for extracts. Shown below is a useful HPLC method which can be used on the solvent extract from a thermoset for the detection and quantification of a wide range of organic additives such as antidegradants. Injection volume

25 μl

HPLC column

Aqua 5 C18 ODS reverse phase column 150 mm x 3.0 mm (or similar)

Mobile phase

A = 75/25 Methanol/Water B = 50/50 Ethyl Acetate/ Acetonitrile

Gradient

Time Initial After 25 mins

Flow rate

2.0 ml/min

Detection

UV detector set at 270 nm

Temperature

40 °C

%A 90 0

%B 10 100

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Analysis of Thermoset Materials, Precursors and Products

The wide applicability of this method, which has also been used successfully at Rapra on an LC-MS system, is due to the mobile phase mixture. The capability of HPLC has been greatly extended by the commercialisation of these affordable LC-MS instruments. The mass selective detector enables unknown samples to be analysed and the antioxidants present to be identified. The LC-MS technique therefore compliments GC-MS and, with it, enables the complete molecular weight/volatility/polarity range to be covered. Bench top LC-MS instruments are proving to be excellent tools in the analysis of all polymer systems of unknown composition to identify and, once this is achieved, quantify additives such as antidegradants. Prior to the advent of LC-MS it was very difficult to use conventional HPLC for this task because of the large range of possible compounds.

6.2 Flow Promoters and Flexibilisers Examples of the flow promoters used in thermoset systems are given in Section 2.3.1. These species are relatively low molecular weight compounds, such as furfural, naphthalene and dibutyl phthalate. These compounds can be detected and quantified using a solvent extraction step followed by an analysis of the extract using GC-MS or HPLC. In some cases (phenyl glycidyl ether in epoxies) reactive diluent flow promoters are used. These become bound into the matrix upon cure, but traces of the unreacted species may still be detectable to enable an identification to be performed. Certain thermosets (e.g., epoxy resins) are brittle and organic modifiers such as polymeric plasticisers have been used to counter this. Examples of these additives include, low molecular weight polyamides, polysulfides and polyamines. In the case of these low molecular weight polymers, removal from the polymer matrix can be more difficult due to the reduced solubility of the compounds. Aggressive solvation conditions using powerful solvents such as orthodichlorobenzene at an elevated temperature (e.g., 140 °C) can be employed and then the extract analysed by techniques such as NMR or GPC with combined LC Transform/IR trapping and detection. Where appropriate, it can also be possible to use elemental analysis to determine the level of sulfur or nitrogen present.

6.3 Pigments Pigments are used extensively in thermoset compounds and can be of one of five main types:

32

1. Inorganic compounds 2. Organometallic compounds 3. Organic compounds 4. Carbon black 5. Metallic pigments White pigments such as titanium dioxide, zinc oxide, zinc sulfide and magnesium carbonate and coloured pigments such as iron oxide (red), molybdate orange, ultramarine blue and vermilion belong to the first group and gold and silver belong to the last group. The analysis of these pigments is relatively easy as they are thermally stable (so can be determined in both the sample ash or in the sample in the as received state) and have a diagnostic metal atom together with a simple chemical structure. Analysis techniques used are therefore elemental methods such as AAS and ICP. The second two groups present the analyst with a greater challenge as there is a very wide number commercially available, they have relatively high molecular weights and so cannot be easily removed from the matrix by solvent extraction and can be thermally labile. One technique which has been used to identify both these types of pigment and inorganic compounds is vapour phase ultraviolet absorption spectrometry at 200 nm (a.36). In this method the samples are powdered and then directly vapourised in the heated graphite atomiser. Thermal ultraviolet profiles of organic pigments show absorption bands between 300 and 900 °C, while profiles of inorganic pigments are characterised by absorption bands at temperatures above 900 °C. Specific assignments are made with respect to temperature, relative intensity and width of the absorption bands. A relatively unknown technique (laser desorption Fourier transform ion cyclotron resonance mass spectroscopy) has also been used (a.37) to identify dyes in polymer systems. A detection limit of 0.1% was obtained, which compared with a limit of 1-2% using an ATR infrared spectroscopy technique. Infrared spectroscopy techniques can be used, as there are standard infrared spectra of a wide range of pigments available. However, this technique has limited success if performed directly on thermosets as the majority give complex spectra with little opportunity for pigments to register in the fingerprint region. Providing that there is only a small total amount of extractable material in the matrix, solvent extraction using a powerful solvent (e.g., chloroform) at elevated

Analysis of Thermoset Materials, Precursors and Products

temperature (e.g., under reflux) for a short period (e.g., 30-60 minutes) can prove satisfactory in removing enough organic pigment for an identification by infrared spectroscopy. Carbon black can be used as a black pigment in products such as inks and coatings. The amount present can be less than 2% and so its quantification by TGA can be difficult due to the small sample size (10 mg) used. An alternative method to quantify the amount of carbon black in such a product employs a tube furnace as much larger sample sizes can be used (e.g., 2 g) and hence more accurate quantifications obtained. It is often the case, though, that any solvent present has to be dried off quantitatively first in order to achieve accurate results.

antimony trioxide and hydrated alumina). Flame retardants are not used extensively as additives in a number of thermoset products, and this is mainly due to the fact that they are inappropriate for the product type (e.g., inks, coatings, adhesives and sealants). It is also the case that, whilst they do not exhibit inherent flame retardant properties, many thermosets (e.g., phenolics and aminoplastics) have very good temperature resistance and so are not easily set alight by ignition sources such as cigarettes. Another feature of thermosets is the use of reactive species in their production that confer flame retardancy to the final product. Examples of this approach include:

6.4 Blowing Agents

1. The use of tetrachlorophthalic anhydride, chlorendic anhydride and tetrabromobisphenol A in the manufacture of unsaturated polyesters

There are two main types of blowing agent used with polymer systems in general:

2. The use of compounds such as dibromoneopentyl glycol in polyether type polyurethanes

1) Chemical – chemical compounds (principally organic) that undergo chemical decomposition at the processing temperature to form a gaseous species (e.g., nitrogen) which will create the cellular structure. Examples include: azo compounds, nitroso compounds, sulfonyl hydrazide compounds and sodium bicarbonate.

3. The use of hexaglycidyl tris(m-aminophenyl) phosphine oxide to make epoxy resins. As with the blowing agents, though, flame retardant additives are used extensively in polyurethane products – the thermoset with the largest market penetration. They are also used in epoxies and unsaturated polyesters.

6.5 Flame Retardants

The amount and type of organic flame retardant present in a polyurethane product can be determined in an analogous way to the low molecular weight organic modifiers (Section 6.2), since this type of flame retardant is usually similar in its extractability. Once the type of organic flame retardant has been determined by IR, an accurate quantification can be obtained by carrying out an elemental analysis for the halogen (or other relevant element, e.g., phosphorus) on the unextracted sample. The extract value itself will rarely provide a meaningful quantification as other species, particularly extracted oligomers, will contribute to it as well. In some instances (e.g., organophosphates) it may be possible to use an HPLC analysis of the extract to quantify the flame retardant. GC based techniques can also be used in some cases, but bromide types present problems for these techniques because of their relatively high molecular weights (> 900). This is another area where the enhanced capabilities of LC-MS are ensuring that it will play a significant role in the future once the appropriate library databases are available.

As with blowing agents, there are two main categories of flame retardant: organic (usually halogen and phosphorus based compounds) and inorganic (e.g.,

The type of inorganic flame retardant additive present in a thermoset can be determined by analysis of the sample directly using an elemental technique such as

2) Physical – low boiling point organic compounds (e.g., dichloromethane or pentane) which volatilise at the processing temperature to create a cellular structure. In the case of thermoset materials, the main product type where blowing agents are used is polyurethane foams, and the type used in this case are the physical blowing agents. It is possible to use headspace GC-MS (either dynamic or static) to identify the physical blowing agent used to blow a foam. Even in the blown state, the high sensitivity of the technique enables an assignment to be made from the small amount of residual blowing agent that will be present. The conditions under which the instrument can be successfully used for this type of application are the same as those given in Section 9.4.

33

Analysis of Thermoset Materials, Precursors and Products

XRF or Edax. Such an approach will provide an identification of the elements present in a semiquantitative way. If required, these compounds can usually be quantitatively isolated from the resin by ashing at around 600 °C. However, care must be taken over some inorganic flame retardants (e.g., antimony trioxide) as they can react with the organic flame retardant present, or break down to produce volatile products (e.g., hydrated alumina), under quantitative ashing conditions, and during analysis by thermal techniques such as TGA. It is also possible to use techniques such as ICP to obtain an accurate elemental determination on the sample in the as received state (e.g., following acid digestion) which can then be used (providing the exact inorganic compound is known or has been elucidated by infrared analysis of an ash sample) to accurately determine the level of the additive. If it is known that hydrated alumina is present in the sample, it is possible to quantify this reasonably well using TGA, by making use of the water loss data. Hydrated alumina loses close to 35% of its weight when it is heated to 550 °C in a TGA experiment.

For some thermoset products low molecular weight monomers (styrene in unsaturated polyesters) or polyfunctional compounds (e.g., diamines in epoxies) are used to crosslink the product. These reactions are rarely carried out to 100% completion and some of the unreacted species will be left in the matrix, the analysis of which will reveal its identity. The most useful technique for this type of work is GC-MS. There are two possible modes of sample introduction: solution injection and dynamic headspace. In the case of the former a useful method of sample preparation involves cryogenic grinding of 0.3 g of the sample, followed by extraction using 2 ml of diethyl ether in an ultrasonic bath for 30 minutes. The resulting extract is then analysed under the following conditions: Instrument

Hewlett Packard 6890/5973 GC-MSD

Carrier

Helium @ 2.0 ml/min constant flow

Injection mode

1 μl splitless (0.75 min; 50 ml/min)

Injection temperature 320 °C Column type

RTX5-MS 30m x 0.25 mm, 0.25 μm film thickness

Column temperature

40 °C for 5 mins, 20 °C/min up to 300 °C held for 12 mins

MS settings

20 to 620 Daltons scanned every 0.33 seconds

6.6 Curing Systems Thermosets such as phenolics have been in existence for many years and so there are a number of classical wet chemistry tests that have been developed to characterise them. Some of these tests can still be of value today as a number of the additives used in thermosets (particularly curatives and accelerators – see Section 2.3.4) are species that are polar and/or thermally labile and so can present problems to modern instrumental techniques such as GC that are not specifically dedicated to a particular function – problems with adsorption effects etc., occurring. Hexamethylene tetramine is used as a hardener in phenol-formaldehyde materials and its determination in these products by titration with perchloric acid has been described by Strupinskii and Zaidenburg. Normal phase HPLC and GPC have both been used successfully to determine an accelerator used in epoxy resin pre-preg formulations. Hagnauer and Setton (a.38) used preparative GPC (with peak identifications performed by IR) and HPLC to obtain quality control fingerprints of epoxy pre-pregs. They also found that the HPLC technique could be used successfully in the quantification of both the resin (tetraglycidylmethylenedianiline and its oligomers) and the accelerator, 3-(3,4-dichlorophenyl)-1,1-dimethylurea.

34

In the case of the dynamic headspace approach a relatively small amount of sample (e.g., 3 mg) is heated in the oven of a dynamic desorption unit and the volatiles produced collected in a cryogenically cooled Tenax filled trap. The experimental conditions are as follows: Dynamic Headspace Instrument

Perkin Elmer ATD 400

Desorption temperature

150 °C for 10 mins

Desorption flow

Helium @ 20 ml/min

Trap collection temperature –30 °C Trap injection temperature

250 °C

Trap outlet split flow

9 ml/min

Trap inlet split flow

off

Split

10:1

Analysis of Thermoset Materials, Precursors and Products

GC-MS The conditions used are the same as for the diethyl ether method with the exception of the following: GC Column temperature –30 °C to 50 °C at 5 °C/min, following by 20 °C/min to 300 °C and then held at 300 °C for 12 minutes Carrier

Helium @ 10.5 psi

For either analytical approach, identification of the diagnostic cure system breakdown species is by reference to mass spectral libraries such as those published by Wiley and NIST. Other libraries such as the Royal Society of Chemistry (RSC) and the EPA/NIH are also useful. The mass spectra of the majority of species of interest are in these libraries and so, providing the knowledge to reconstruct cure systems is available, successful attempts can be made. It is also the case that systems such as unsaturated polyesters employ peroxides to initiate the reaction between the reactive monomer (styrene) and the unsaturated polyester polymer. It is also possible to use headspace and solution injection GC-MS techniques to identify the type of peroxide used in a crosslinked product. However, one problem associated with the task is that a number of peroxide curing agents breakdown to give more than one product and a number of these are common to more than one peroxide species. This is demonstrated in Table 10. Other examples of the curatives and hardeners used in thermosets are shown in Section 2.3.4. It can be seen that a number of these species are polar (e.g., oxalic acid – phenolics, triethanolamine – melamineformaldehyde, acid anhydrides – epoxies). These types of compound can prove problematic with GC based analytical systems because of their reactivity, adsorption onto liners within the injection system and sites on the column being a major problem.

Although it is possible to set up dedicated systems using special deactivated liners and columns, or to carry out derivatisation reactions, these steps can have the drawbacks of being expensive, time consuming or both. Fortunately, the increased availability of LC-MS systems has provided an attractive third option for the analysis of these types of species. LC-MS methods for both acidic and basic species have been developed at Rapra. The following are examples of the different analysis conditions that have been used successfully. In both cases an electrospray type head has been used. This type of head is more applicable than an APCI head to the analysis of species, such as acids and bases, that are already ionised in solution. Although the degree of fragmentation can be altered with the electrospray head, by adjusting the fragmentation voltage, it is usually the case that the parent molecular ion dominates the spectra obtained. 1) LC-MS method for the determination of acidic species in polymer extracts: Injection volume 2 μl Mobile phase

Solvent A Solvent B

Flow rate

0.5 ml/min

Acetonitrile 0.1% acetic acid in distilled water

Mobile phase programme 0 min 50% A and 50% B After 7 min 80% A and 20% B Total run time: 12 min Head polarity mode

Negative

Mass scanning range 80 to 500 Fragmentor voltage

180

Table 10 Diagnostic species of peroxide curatives Peroxide curative

Diagnostic species

Benzoyl peroxide

Benzoic acid, benzene and biphenyl

Methyl ethyl ketone peroxide Cyclohexanone peroxide

Methyl ethyl ketone Cyclohexanone

35

Analysis of Thermoset Materials, Precursors and Products

2) LC-MS method for the determination of basic species in polymer extracts Injection volume Mobile phase

Flow rate

7.1 Dielectric Analysis

5 μl Solvent A

Acetonitrile

Solvent B

5 mM ammonium acetate in distilled water

0 min After 5 min After 20 min Total run time

8% A and 92% B 11% A and 89% B 90% A and 10% B 23 min

Positive

Mass scanning range 80 to 500 Fragmentor voltage

80

It is also possible to perform such analyses using single ion monitoring (SIM) to improve the detection and quantification of specific species. Solvent based paints are an important class of thermoset products and these ‘dry’ by a combination of oxidation and polymerisation. To ensure that this process occurs in hours rather than days organometallic (e.g., resinates, linoleates and naphthenates) compounds are used as catalysts. A variety of metal salts are used including cobalt, lead, manganese, calcium and zirconium. These metallic species can be identified in a paint sample by the use of AAS, taking care to ensure that allowances are made for any inorganic pigment. The organic section of the molecule can be determined by a chromatographic method, e.g., GC-MS. The move away from lead on health and safety grounds has stimulated research into non-metallic catalysts, an example being orthophenanthroline. Lueschen (291) has described the use of a range of chromatographic techniques (e.g., GC, HPLC and GPC) for the characterisation of accelerators, curing agents and their reaction products in adhesive samples.

36

Dielectric analysis (DEA) can be used to study the cure of a number of products. Examples include: 1. Room temperature curing urethane adhesives used for bonding in the automotive industry 2. Silicone potting compounds used to protect electronic components

0.5 ml/min

Mobile phase programme

Head polarity mode

7 Cure Behaviour Studies

3. High performance, high temperature curing polyurethane resins used in electronics applications 4. Phenolic resins and their fibre filled composites 5. Unsaturated polyester systems. The study of the curing processes in thermosets was one of the earliest uses of commercial DEA instruments. DEA offers the advantages over the other thermal techniques of being less affected by the loss of volatiles during cure (compared with DSC/DTA) and of being able to record data on liquids (compared with DMTA/TMA). The technique is also more sensitive than DSC to curing reactions. When performing an experiment the sample is placed in contact with a sensor (electrode array). The electrode array applies an oscillating voltage to the sample and senses the response of the material to the applied voltage signal. Certain instruments (e.g., the system from TA instruments) also use disposable sensors which eliminates the need for clean up procedures between samples. Data can be obtained directly on samples in a powdered form, although better results are obtained if samples are ground into a powder to ensure better contact with the electrodes. The results are obtained in the form of a plot of log of conductivity as a function of sample temperature. Experiments can be carried out over a wide range of frequencies. For example, in the analysis of a phenolic resin, the following series is indicative of the frequencies that could be used : 0.3, 1, 3, 10, 30, 100, 300, 1000, 3000, 10000 Hz. The following important product values can be obtained from experiments using this technique: a) Glass transition temperature b) Onset of flow

Analysis of Thermoset Materials, Precursors and Products

c) Minimum resin viscosity point

7.2 Differential Scanning Calorimetry

d) Start of cure e) Onset of crosslinking f) Completion of cure Wetton and co-workers (383) have shown that DEA and DMA can be used in a complimentary way on resins of the phenolic and imide type (i.e., those that cure via a condensation reaction) to produce a viscosity and modulus/permittivity correlation chart. The basis of the work is that DMA gives a strong response through tan delta during the gelation and initial crosslinking phase, which does not register well with DEA because it is a bulk (i.e., large scale) event. As the crosslinking reaction continues, DEA comes into its own as the small structural events associated with this part of the cure cycle are not picked up as well by DMA. Hence, it is then possible to use DEA measurements in isolation and convert the results into mechanical property data. Such tests can also be used as a quality control check. Figure 11 shows how DEA can be used to obtain comparative cure data on different systems, in this case two ambient temperature curing polyurethane products.

DSC can also be used to study the curing of thermosets. Curing is an exothermic reaction and so registers in a plot of specific heat against time. Two advantages of DSC are that only a small amount (e.g., 5 mg) of sample is required and no specific sample geometry is necessary. If loss of volatiles from the sample pan during curing is a problem (e.g., by the generation of an endotherm), so-called high pressure sample pans can be used. These are effectively larger aluminium pans which provide a better seal when crimped. Figure 12 shows a comparison of the ambient pressure and high pressure pan techniques for the determination of the curing properties of a phenolic resin. It can be seen that far superior data is obtained with the high pressure approach. It is possible to use the DSC in a number of ways. It can be used as a quality control tool to measure the progress and total extent of a cure. The exotherm obtained is very specific to a particular product and so standard thermograms need to be available to assist in the interpretation of the data. Also, its ability to record data on small samples can be used to depth profile a finished product to examine the degree of cure through

Figure 11 Comparison of the curing behaviour of two different polyurethane resin systems at 25 °C using DEA

37

Analysis of Thermoset Materials, Precursors and Products

Figure 12 Comparison of ambient and high pressure DSC for monitoring the cure of a phenolic resin

a section – incomplete cure being shown up by a secondary exotherm, as opposed to a completed cure where no exotherm will be apparent. Another major application for DSC is to study the reaction kinetics of crosslinking reactions. For example, the data obtained can be used to determine the order of the reaction and will show if the reaction is autocatalytic or not. It should be remembered though that the use of DSC to determine kinetics is based on two assumptions: 1. The heat flow relative to the instrument baseline is proportional to the reaction rate. 2. The temperature gradients through the sample as well as the temperature difference between the sample and the reference are small. These assumptions are usually reasonable provided small sample sizes (up to 10 mg) and slow heating rates (or isothermal experiments) are used. Prime (a.39) has discussed the various approaches to determining the kinetics of a thermosetting reaction by DSC but, while it is a popular technique for this application, the published results of an inter-laboratory trial (353) show that a number of experimental conditions as well as instrumental idiosyncrasies can interfere with reliable determination of the heat of reaction – the basis of the kinetic calculations. In particular, even with curing reactions that do not involve volatile by-products, reactants with low vapour

38

pressures can cause problems with accurate measurements if samples are not properly contained. Sepe (251) has summarised other considerations that prevent DSC from being used as a reliable method for absolute determinations of degree of cure. The usefulness of DSC in the monitoring of thermoset cures is illustrated by the fact that the determination of the heats and temperatures of reaction in one such system, phenolic resins, is the subject of an international standard, ISO 11409. A useful comparative approach, is that where a polymer system gives a glass transition temperature that is easy to determine by DSC, this can be used to follow the reaction with respect to the degree of conversion of the monomers. In recent years the technique of modulated DSC (MDSC) has been developed and workers in the field have applied the technique to the curing of thermosets such as epoxy resins. Using a DSC in the modulating mode provides information about the reversing and non-reversing characteristics of thermal events. This type of information can assist in revealing certain aspects of a cure, such as a comparison of the rate of heat capacity change during the initial stage (chain extension) of a cure compared to that during the final stage (crosslinking). Also, because in certain thermosets the glass transition temperature is close to the temperature at which

Analysis of Thermoset Materials, Precursors and Products

curing begins, the broad exotherm can obscure it. Since curing is a non-reversing phenomenon by MDSC, separation and detection of the Tg (a reversing phenomenon) is possible. Differential photocalorimetry (DPC) is an adaptation of DSC which uses an ultraviolet or visible light source to study the curing behaviour of photo reactive systems. A commercial instrument is available from TA Instruments and the technique can be applied to a number of crosslinking products, e.g., inks, coatings, adhesives and dental materials. As with DSC, kinetic studies can be performed by the use of isothermal experiments performed at different temperatures or multiple dynamic heating runs at different heating rates. This type of approach has been used to compare the rate of photo curing of two types of photo initiator in a single oligomer based system (352).

7.3 Dynamic Mechanical Thermal Analysis/ Dynamic Mechanical Analysis Because the storage and loss modulus data can be used to calculated viscosity, DMTA can be used to directly monitor the curing process. However, the technique is best suited to investigating incomplete cure in finished solid products, or crosslinking reactions occurring in very viscous liquids. This is because the most popular mode of operation involves the analysis of solid samples having the approximate dimensions 2 cm x 1 cm x 1-2 mm. The examination of viscous liquid systems is possible by using a virtually inert support. The support is analysed separately and the data obtained subtracted from the combined data. It is also possible though to use parallel plate methods which can cope with powders and pastes. It is these physical limitations that give DEA and DSC a big advantage over this technique for this type of work. The key parameters for this type of work are the shear storage modulus (G´), the shear loss modulus (G´´) and the complex viscosity which is given as the complex shear modulus divided by the phase angle. Tan delta can also be of value since the gelation point of the system is the point where G´=G´´ and tan delta is unity. The value of tan delta will typically reach a maximum as the complex viscosity reaches a minimum, and the final value for tan delta when the cure is complete will be indicative of the crosslink density of the material. As the curing starts G´ and G´´ cross over and this is the gel point, which is very dependent on temperature. Further crosslinking results in an increase in both moduli until an equilibrium point is reached which is also dependent on temperature. By running a number

of experiments at different isothermal temperatures, DMTA can be used to assess the processibility of thermosets such as unsaturated polyester resins. Once such temperature-cure rate and time-temperature relationships have been established using multiple single temperature runs, quicker, dynamic heating runs can be used as a quality control tool (310) although some accuracy is sacrificed. DMTA is very useful for determining the state of cure of heavily reinforced thermoset products such as brake linings. This parameter is very important in such products as it will have an important influence on their performance in service. The DMTA is ideal for this type of evaluation as it measures the change in modulus of the whole sample and this property changes greatly as the material passes through its Tg. If a sample is thought to be undercured, heating it will not only shift the tan delta damping peak to a higher temperature but it will also lead to an increase in modulus before and after the Tg. Phenolic resins display excellent retention of physical properties at elevated temperatures but tend to require post curing to develop maximum stability. Phenolics can also be susceptible to oxidation, which can cause embrittlement and reduce strength, and so care has to be taken in the post-curing step to minimise this type of degradation. The DMTA is capable of showing the increase in modulus and Tg that occurs with a good post-curing regime, but can also reveal the embrittlement effect of oxidation that results from overheating, in which case the material displays no damping characteristics in the tan delta plot, and the eventual decrease in modulus as further oxidation of the material reduces strength. This capability is important since samples that have both of these inherent defects show no outward sign of surface softening or blistering.

7.4 Thermal Mechanical Analysis The TMA instrument can be used to determine the gel time of systems such as epoxy resin-glass prepregs. The gel time is defined as the time from when the material begins to soften until gelation (the irreversible transformation from a viscous liquid to an elastic gel) occurs. The gel time is a critical processing parameter since after it the material is no longer able to flow and be processed. To determine gel time the TMA is used in a particular probe configuration (the parallel plate rheometry mode) and

39

Analysis of Thermoset Materials, Precursors and Products

its ability to monitor dimensional changes can be used to determine gel time and viscosity values.

has been used to study the cures of a number of thermoset systems. For example:

It is also possible to use the sensitivity of the TMA technique to a material’s Tg to determine the extent of cure of a thermoset, since the Tg will increase with increasing cure state. If however, the material is heavily filled or reinforced, this may prove difficult since the response to Tg will decrease with the decreasing polymer fraction. In this case the dynamic version of the technique (DMTA) will be more effective as it determines the change in modulus, a property that varies greatly as a material passes through its Tg.

1. Polyurethanes 2. Epoxy resins

7.5 Scanning Vibrating Needle Curemeter As liquid polymer systems cure there is a significant change in viscosity early on but, more importantly, a change in their damping and elastic properties throughout the cure. It is therefore possible to follow the progress of a cure by obtaining a continuous measurement of the storage (elastic) modulus and damping (loss) modulus. Rapra Technology Limited has developed an instrument, called a Scanning Vibrating Needle Curemeter (SVNC), which uses this approach and this

3. Silicones 4. Acrylics The instrument is capable of monitoring changes in the viscoelastic properties of the polymer matrix after the gel point (the point at which there is no further change in viscosity) of the cure has been reached. As the name suggests the working part of the instrument is a vibrating needle and the cure is monitored by measuring the change in resonance characteristics of the needle as the sample cures. In the initial stages of a cure, when the change is purely viscous, the damping of the needle’s vibration increases and the amplitude decreases. When gelation occurs and the sample develops elastic character, an increase in the resonance frequency of the sample occurs. The resonance frequency continues to increase as the storage modulus (or hardness) increases and the cure is complete when no further changes take place. Figure 13 shows the SVNC data obtained during the curing of a liquid polysulfide sealant.

Figure 13 Use of the Rapra SVNC to monitor the cure of a liquid polysulfide sealant

40

Analysis of Thermoset Materials, Precursors and Products

It is possible to produce continuous cure profiles and to use the instrument to determine the effect that changing the composition of the polymer system (e.g., crosslinking agent or catalyst type) or the cure conditions (e.g., temperature) have on the cure characteristics.

3. Addition of a non-solvent to a solution of the reaction mixture to precipitate out the high molecular weight reaction products and leave the monomer in solution. Direct injection work is then carried out on the solution. Applications for which this type of approach is successful include the determination of low molecular weight monomers such as styrene in unsaturated polyester cures and methylmethacrylate in crosslinked acrylics.

7.6 Chromatography Techniques Chromatographic and spectroscopic techniques have been used by Donnellan and Roylance (377) to study the curing reactions of a series of bismaleimide resins varying in the ratio of N,N’-bismaleimido4,4’-diphenylmethane and methylene dianiline. A Michael type addition reaction was found which gave linear chain extension and a double bond addition reaction which produced crosslinks via the double bond of the maleimide group. Lowering the curing temperature, or increasing the methylene dianiline content, were found to favour the chain extension reaction and lead to lower crosslink densities.

7.7 Spectroscopy Techniques Modern instrumentation now enables Dielectric Relaxation Spectroscopy (DRS) to monitor chemical (e.g., crosslinking) or physical (crystallisation) changes in real time. It is therefore a useful technique for the study of thermoset crosslinking reactions and one popular system is the reaction of epoxy resins with amine hardeners. The use of DRS for this type of application has been reviewed by Senturia and Sheppard (389). Magion and Johari have published a number of papers on the reaction of the diglycidyl ether of bisphenol A with diaminodiphenylmethane and/or diaminodiphenylsulfone (384, 385).

Gas chromatography has been widely used in cure studies where one or more of the reactants are volatile and thermally stable enough to be amenable to the technique. Aliquots of the reaction mixture are removed at regular intervals and the amount of the reactant(s) quantified. An important aspect of the methodology is the efficient and consistent removal of the analyte from the sample matrix. The three principal routes used are:

Infrared spectroscopy has been used extensively to study cures. One common approach is to monitor the decrease of an absorption band associated with one of the reactants together with the increase of one associated with the cured product that is being formed. Some examples are given in Table 11.

1. Heating of a solution of the sample in a headspace vial, with subsequent analysis of the headspace.

Figure 14 shows how following the decay of the free isocyanate absorption band can be used to monitor the curing reaction of a polyurethane system as it is heated at a rate of 0.5 °C/min.

2. Solvent extraction of the solid matrix followed by direct injection of the extract into the chromatograph

Table 11 Bands used for monitoring cure in different polymer systems Polymer System Polyurethanes Epoxies

Bismaleimide

Reactant band

Product band

Isocyanate

Urethane

Epoxide

Ether

Amine

Hydroxyl

Amine

C-N-C or =C-H maleimide groups

41

Analysis of Thermoset Materials, Precursors and Products

Figure 14 Decay of the free isocyanate band in a polyurethane system as it is heated at 0.5 °C/min

The use of attenuated total reflectance (ATR) sampling accessories enables infrared radiation to penetrate into the surface of a reactive mixture and record an infrared spectrum. The development of continuous data collection software has enabled this type of technique to monitor cures in real time. This approach has been used for the in situ monitoring of the reactions that occur in the production of melamine-formaldehyde resins (25). The ability to study the reactions in realtime enables the technique to be used for in situ process control during manufacturing.

materials was 15N-enriched metaphenylenediamine and its curing reactions with a bisphenol A epoxy were studied using both 13C and 15N NMR.

In the case of solid samples where transmission of the IR beam is not possible and the surface not smooth enough for the use of the ATR approach, the photoacoustic accessory can be used. This method involves placing the sample in a sealed cell with a single window for the incoming IR beam and monitoring pressure changes in the cell as heat is evolved. A drawback of this technique is that the measurement times are relatively long and so it is difficult to use it for dynamic cure studies. The technique has been used to determine the residual unreacted alkene groups present in cured polyfunctional acrylate surface coatings (390).

Electron spin resonance spectroscopy (ESR) has been used to make direct measurements of the monomer and radical concentrations in crosslinking systems. Using the near-infrared spectrum of the C=C bond in methyl methacrylate Carswell and co-workers (387, a.40) studied the reaction of this monomer with ethylene glycol dimethacrylate. The variation of the concentrations of both C=C bonds and free radicals with time was established and the kinetics of the reaction investigated.

Solid state (cross-polarisation and magic angle spinning) 13C NMR techniques can be used on semi-solid samples and have been applied by So and Rudin (386, 394) to phenol-formaldehyde cures. The curing reaction produces methylene bridges between the aromatic rings and so the extent of the reaction can be obtained from the ratio of bridge methylene to aromatic carbons.

7.8 Thermally Stimulated Depolarisation The ability of NMR to accurately monitor the change in the concentration of particular chemical groups (via the integrals of their chemical shifts) has resulted in it finding many applications for monitoring the curing of thermoset materials. A number of systems have been used including 13C and 15N instruments for studying epoxies. Chain extension (amine and epoxy groups) and crosslinking (hydroxyl and epoxy groups) reactions can be monitored and the relative abundances of each in a particular system determined. In one study (397) one of the starting

42

This technique is sometimes referred to as Thermally Stimulated Current (TSC) and it has similar capabilities to DMTA and DEA. TSC exhibits greater sensitivity to fine structural detail within the polymer matrix and so offers the possibility of being able to be used to study different structure-property relationships. The principle of the technique is that a high voltage is applied to a polymer at an elevated temperature to orient

Analysis of Thermoset Materials, Precursors and Products

the dipoles. The sample is then cooled very rapidly (i.e., quenched) to freeze in the orientation. The external field is then removed and the sample is heated at a constant rate, undergoing depolarisation at the temperatures associated with particular structural relaxations (e.g., Tg). The depolarisation current produced is plotted as either current density or dynamic conductivity against temperature. The plot of current density against temperature is analogous to a tan delta against temperature plot for DMTA or DEA. Because the system operates at very low frequencies it can detect events that may overlap with the higher frequency methods. Because a conductive substrate can act as one of the electrodes in an experiment, the technique has been used to study paints, films and adhesives applied to metal surfaces (289). The technique has also been used to study the properties of epoxy/glass bead composite materials (329).

7.9 Wet Chemistry Techniques A quantitative solvent extraction determination has proved a simple and relatively quick method to investigate the degree of cure of a thermoset type material. By careful choice of the solvent to ensure compatibility with any polymer chains that are not bound into the network a comparative assessment of the degree of cure can be obtained. It is usually advisable to have a control sample which is fully cured and then to compare the extract values between this sample and the unknowns; a higher level of extract indicating a lower level of cure. One popular example of such an approach is the use of a quantitative acetone Soxhlet extraction to assess the degree of crosslinking of a RIM polyurethane. In such systems a small variation in the proportion of isocyanate and polyol can have a significant effect on the cure and hence the amount of low molecular weight extractable polyurethane present. For example, the value can vary from around 8% for a good sample to 16% for a poor one (146). It is also possible to use a Soxhlet extraction with acetone to determine the extractable (i.e., free fraction) and the non-extractable (i.e., gel fraction) of other cured thermosets such as phenolics and epoxy resins. As with the polyurethane example, this type of test works best when carried out in a comparative manner to compare known and unknown samples. A classic wet chemistry approach to the investigation of cure involves titrimetric analysis. An example of this is an investigation into the kinetics of an acid/epoxide endlinking cure where the acid content of the reaction

mixture is determined by titration against a weak (e.g., 0.1M) alcoholic potassium hydroxide solution with phenolphthalein as the indicator. This type of study is described by Willoughby (391). In the case of polyurethanes, the ‘amine equivalent’ method can be used in the pre-gelation stages by reacting the free isocyanate groups with excess amine and back titrating with acid. This type of reaction has been used to monitor the reaction of isocyanates with both triols (399, 402).

8 Surface Analysis of Thermosets There are a number of analytical techniques that can be used to obtain data on the surface of a thermoset. Three of the techniques (IR and Raman microscopy and Edax) have been mentioned in Sections 3.2.1, 3.2.5, and 3.2.6. It can be argued that these techniques have come into being as a logical development of the original, more general, techniques. There are however a number of analytical instruments that have been developed with the specific intention of analysing surfaces. Three of the principal ones will be covered in this section.

8.1 X-Ray Photoelectron Spectroscopy (XPS) In this case the surface of the sample is irradiated with soft X-rays. These X-rays are sufficiently energetic to cause photoemission of electrons from the core levels of atoms present on the sample surface. The photoelectrons generated are collected and passed to an electron energy analyser and detector. The measured kinetic energy (KE) of an electron is given by: KE = hv - BE – σ where hv = energy of the X-ray photon BE = binding energy σ = work function of the spectrometer The binding energy of a given core electron is characteristic of the element and it is this which enables the elements on the surface of a sample to be identified. It is also possible to carry out quantitative work by measuring the relative intensities of the photoemission from each of the elements present. The

43

Analysis of Thermoset Materials, Precursors and Products

binding energy of a core level depends principally on the charge on the nucleus of the atom concerned and smaller changes are induced as a result of chemical bonding. Although small, such charges are measurable and provide a means of studying the chemistry of the sample surface (a.41, a.42). Because only electrons from the top few atomic layers will have sufficient energy to escape, the technique is very surface specific and results are normally obtained from between 5 and 10 nm depth at a detection limit of around 0.1 atom percent. The analysis area is typically 3-10 mm2 and all the elements with only the exception of hydrogen can be detected. Because of its ability to determine surface chemistry, XPS can be particularly useful in the analysis of polymer surfaces to see if oxidation has taken place and, if so, what functional groups (e.g., ester, acid, aldehyde) the oxygen is present in. Another application is the analysis of polymers to determine if certain surface treatments (e.g., corona discharge) have been carried out satisfactorily. In common with the other surface analysis techniques, it can also be used to investigate surface contamination problems and to determine the composition of the fracture surfaces in adhesion failures.

8.2 Laser Induced Mass Analysis (LIMA) In the LIMA technique, the surface of the sample is subjected to a pulsed UV laser which is sufficiently energetic to volatilise a small volume (about 1 μm cube) of material. The ionised fragments in this volume are then separated and identified by means of a time of flight mass spectrometer. Both negative and positive fragment data can be obtained. The analysis area in a LIMA experiment is typically 1-2 μm, the analysis depth 0.25-0.5 μm and the detection limit 10-100 ppm. The technique has the ability to detect all of the elements in a qualitative way. The technique is very useful for determining compounds on the surface by means of these elements and molecule fragments, but it is very sensitive, and care must be taken to ensure that the surface is not contaminated (e.g., by handling without gloves) and that the representative control samples are available to assist in the interpretation of the data.

44

Its sensitivity and surface specificity make it ideal in the detection of very low levels of contamination/ modification. For example, the detection of a monolayer of silicone contamination of a plastic part that was hampering the wetting of a paint. It can also be used to analyse particulate impurities, fibres and defects in surface coatings. LIMA can also be referred to as Laser Microprobe Mass Spectroscopy (LAMMS).

8.3 Secondary Ion Mass Spectroscopy (SIMS) In this technique the sample surface is bombarded by a primary ion beam (positive ions of argon, caesium, oxygen or gallium). These primary ions impart energy to the surface and, as a consequence of the collisions produced, ions, atoms and molecular fragments (called sputtered particles) are ejected. The primary ions may penetrate several atoms layers into the surface, but the sputtered particles only come from the outer 2-3 atom layers. In common with the other two techniques, therefore, SIMS is very surface specific: it is possible to restrict it to a single monolayer. The analysis area is typically 150 μm, the detection limit is 1 ppm and all the elements are detectable. Two types of SIMS experiment can be carried out: static SIMS and dynamic SIMS. In the former case, the surface is bombarded with low energy ions and molecular and atomic fragments are produced without the experiment changing the nature of the surface appreciably; the surface chemistry can therefore be investigated. Dynamic SIMS uses high energy ions to obtain highly sensitive elemental data down to ppb levels, but the structural information is lost. In the case of static SIMS, dedicated libraries are required to enable the mass spectra of the fragments to be identified (a.43). SIMS can be very good at solving surface related problems. For example, when a glass reinforced polyester resin which was not responding well to wetting with a paint was initially analysed by XPS only silicon, hydrogen, carbon and oxygen were apparent. Analysis of the same surface by static SIMS enabled the mass spectrum of the sputtered top layer fragments to be determined and the presence of m/e ions at 43, 73 and 147 confirmed that a polydimethyl siloxane was present. The initial XPS data could not differentiate between silicon from the siloxane and silicon from the glass fibres.

Analysis of Thermoset Materials, Precursors and Products

SIMS can also be used to determine where organic additives, such as flow promoters, have migrated onto the surface of a thermoset product.

subambient transition. As the heat ageing continues, the Tg will shift to a lower temperature as the crosslink matrix begins to break down. These effects can be used in the comparison of a failed sample with an unaged one to investigate if heat ageing is the cause of failure.

9 Failure Diagnosis 9.3 Contamination Problems It is an unfortunate fact that thermoset products fail in service. One of the major reasons for this is an incorrect formulation of the product initially, which is a technological failing, the other is where the formulation is correct for the application, but where there has been a problem in the mixing/processing side, leading to a product that does not meet the specification. Other reasons for failure include the presence of contaminants and unwanted interactions with the nearby environment (e.g., emission of an unpleasant odour or the ‘fogging’ of a nearby substrate such as a window). Analysis work on the thermoset product can establish the reason and/or origin of these problems.

9.1 Compositional Problems On occasions a thermoset product may fail in service and work needs to be undertaken to find out why. If it is suspected that the composition of the product is not correct, for example that an incorrect cure system or filler has been incorporated into the compound, then the appropriate species specific tests that have been discussed earlier can be carried out. If possible, it is advisable to conduct the analysis alongside that of a sample known to be of the correct composition. This ensures that no product specific matrix effects/ interference reactions will affect the data obtained and hence the conclusions reached. A surprisingly large number of failure problems can be solved by carrying out a simple series of tests that include a polymer identification check by IR, a bulk compositional analysis by TGA, and an identification of the major additives such as fillers or organic modifiers.

9.2 Heat Ageing Heat ageing of thermosets usually results in a reduction of the damping properties of the material. In practice this results in a reduction of impact strength and it can be studied using the DMTA technique where it manifests itself in a reduction of the peak height of tan delta for either the Tg of the material, or an important

9.3.1 Solid Contaminants Thermoset products can fail, both aesthetically and physically, because of solid contaminants. Chemical resistance and electrical failure are less likely as this type of contamination is not usually present at a high enough concentration. The contaminants can enter the product stream either in the ingredients used in the production, or during the manufacturing stage (e.g., mixing, extruding or moulding). Because this type of contamination is in the form of solid, discreet entities, it makes their removal from the product relatively easy. Once removed the microscopic techniques IR and Edax are excellent at obtaining assignment data in a cost effective way. Where enough of the contaminant is obtainable (e.g., 1 mg), and if a mixture is suspected, a bulk composition by TGA can be obtained. If identification problems are still occurring, more sophisticated techniques such as pyrolysis GC-MS can be employed. If it is suspected that the contaminant is, or contains, a metal, then AAS can be employed on either an isolated region of the product that is affected or, if enough examples can be collected, on the contaminant itself.

9.3.2 Liquid Contaminants Where the contamination is in a liquid form and present in inclusions in the product a similar analytical approach can be used as that described above – Edax, infrared microspectrometry and AAS can all be used. However, the fact that the contaminant is now a liquid makes its removal from the matrix by heating possible, and techniques such as dynamic and static headspace GC-MS can be used. These provide the additional benefit of being able to separate and identify the components of a mixture. It is also the case that liquid contaminants in the precursors of thermosets can cause quality control

45

Analysis of Thermoset Materials, Precursors and Products

problems. For example, moisture can affect the processing of mouldable epoxy resins. This moisture can influence flow in the mould and can result in other processing problems such as blistering and a decrease in hot strength. Moisture evolution analysis using specific analysers can ensure that this type of contaminant is detected and quantified. It is also the case that exposing epoxy moulding compound to moist air can cause some pre-curing to occur. This is detectable by monitoring the Tg of the compound by TMA (change in expansion coefficient), since the Tg will decrease as the reaction with water in the atmosphere takes place.

9.4 Odour and Emissions Problems The continuing drive to improve customer care and the high profile of health and safety issues, has led to pressure on the suppliers of thermoset components to certain industries to minimise odours, and volatiles in general, from their products (a.44). This is particular true of the automotive industry. There are a number of specific tests that automotive companies insist that thermoset components manufactured by suppliers have to pass. An example of such a test is the VW emissions test which involves placing the component in a cell of given dimensions and heating the cell for a given time at a specified temperature. Rather than carry out a detailed analysis of the components liberated from the thermoset component, the result is expressed in terms of ppm of total organic compounds as determined by an organic vapour analyser (OVA). Limits are given as to the permissible concentrations allowed. For quality control purposes it is the case at present that human smell panels will be used in preference to instrumental analytical techniques which do not yet adequately mimic the human response. The practical drawbacks to this approach are leading to a lot of research going into ‘electronic noses’ utilising a number (e.g., 32) of sensors based on organic conducting polymers. These devices enable fingerprints of satisfactory products to be recorded which are used as references for quality checks. One of the most useful techniques to establish the origin and composition of sample emissions is headspace GC-MS. It is advisable to use the dynamic form of headspace sampling as this enables the volatiles from the sample to be concentrated. This benefit is important as some chemical species can

46

cause an odour problem at very low levels due to the specific sensitivity of the human nose. For example, amine catalysts used in polyurethanes can cause odour problems, but some amines have a very low olfactory threshold, such as trimethylamine (fishy odour) which has a limit of 0.47 ppb. For this type of work a dynamic headspace sampler (e.g., the Perkin Elmer ATD 400) is operated in a diffusion mode where the sample is heated at a relatively low temperature (e.g., 50 °C), which helps to ensure that additional volatile species are not generated due to degradation of the sample, for a relatively long period of time (e.g., in excess of 30 minutes). The odour species collected in the trap of the dynamic headspace sampler can then be analysed under the following conditions: Headspace trap injection temperature

200 °C

GC column type

SGE RTX5 MS 30 m x 0.25 mm, 0.25 μm film

GC column temperature

–30 °C to 50 °C at 5 °C/min and then 20 °C/min

(cryogenic cooling)

to 320 °C

MS conditions

20 to 450 atomic mass units scanned every 0.33 seconds

10 Conclusion This review describes the analysis of thermoset precursors, polymers, compounds and products in as comprehensive a way as is possible within the format of a Rapra Review Report. The subject matter has been kept as broad as possible to maximise the usefulness of the publication, whilst trying to maintain a reasonable balance between breadth and depth. The abstracts and additional reading references provided should greatly assist the analyst who requires more information. Although an attempt has been made to include as much information as possible, the subject of thermoset analysis is so large that it is inevitable that certain analytical techniques and methods will have been excluded or only given a cursory mention. For the future, liquid chromatography-mass spectroscopy systems will soon dominate this type

Analysis of Thermoset Materials, Precursors and Products

of chromatography at the expense of the traditional HPLC and TLC systems. It is also the case that commercial LC-MS instruments are now available at a reasonable cost. These instruments have provided a quantum leap in analytical capability and, in combination with GC-MS, will greatly improve the efficiency and accuracy with which the analysis of additives such as antidegradants and cure system species can be carried out. The combination of these two types of instrument enables the full spectrum of polarity and molecular weight to be covered. There are also developments in the GC-MS field with the availability of tandem or two dimensional (i.e., GCGC) mass spectrometer instruments which provide the analyst with the ability to use two different types of analytical column in a single analytical run on a sample. This feature is particular useful in the analysis of complex extracts from polymer matrices and will also greatly assist in the identification of functional additives. In the case of the surface analysis techniques (SIMS, XPS and LIMA), these are becoming increasingly routine and, as a result, cost effective for consultants to use in characterisation and failure diagnosis work and therefore an expansion of their use is guaranteed. In the thermal analysis field, a number of developments have occurred in recent years, with modulated temperature forms of TGA, DSC and TMA being brought out by manufacturers. Modulating the temperature enables these techniques to deliver better, more informative data on samples. Another development within the thermal analysis group is the micro-Thermal Analysis (micro-TA) instrument. This technique combines the topographical mapping capabilities of a scanning probe microscope with the ability to perform localised thermal analysis (DTA and TMA) on a micron scale. The instrument is also capable of being coupled to a GC-MS and the chemical identification of specific features undertaken by the analysis of pyrolysis induced volatiles. The analysis of cure is of particular importance in thermoset products and increasing use is being made of in situ infrared spectroscopy techniques, particularly those based on attenuated total reflection methods. These instruments enable real-time cure system data to be produced. Another infrared technique which is gaining in popularity is the time resolved 2D (two dimensional) technique. This also tends to be an ATR type technique and is used to study the chemical interactions associated with such events as the diffusion of water into a cured

epoxy resin matrix and the behaviour of the crystalline and amorphous regions within a polymer when the system is put under strain.

Additional References a.1

L. Sabbatini and P.G. Zambonin, Eds., Surface Characterisation of Advanced Polymers, VCH, 1993.

a.2

J.L. Koenig, Spectroscopy of Polymers, Elsevier, 1999.

a.3

T.R Crompton, Manual of Plastics Analysis, Plenum, 1998.

a.4

T.R. Crompton, Practical Polymer Analysis, Plenum Press, 1993.

a.5

A.H. Fawcett, Ed., Polymer Spectroscopy, Wiley, 1996.

a.6

Thermal Analysis, Technical Literature (Theory and Applications), TA Instruments, 1994.

a.7

C.P.A. Kappelmeier, Ed., Chemical Analysis of Resin Based Coating Materials, Interscience Publishers, 1959.

a.8

I. Gyenes in Titration in Non-Aqueous Media, Iliffe Books, 1967, 261.

a.9

C.P.A. Kappelmeier, Verfkroniek, 1954, 27, 291.

a.10

C.P.A. Kappelmeier, Farben Ztg.,, 1935, 40, 1141.

a.11

F.W. Ferckow, Farben Ztg., 1939, 44, 33.

a.12

S.P. Frankoski and S. Siggia, Anal. Chem., 1972, 44, 507.

a.13

M.T. Grubb, J. Am. Chem. Soc., 1954, 76, 19, 3408.

a.14

G.A. Stenmark and F.T. Weiss, Anal. Chem., 1956, 28, 1784.

a.15

A. Krishen in Size Exclusion Chromatography, Ed., T. Provder, ACS Symp. Ser. 245, American Chemical Society, Washington DC, 1984, Chapter 16.

a.16

F.P.B. Van der Maeden, M.E.F. Biemond and P.C.G.M. Janssen, J. Chromatogr., 1978, 149, 539.

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Analysis of Thermoset Materials, Precursors and Products

a.17

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Abbreviations and Acronyms AAS

atomic absorption spectroscopy

APCI

atmospheric pressure chemical ionisation

API

atmospheric pressure ionisation

ATR

attenuated total reflectance spectroscopy

a.28

K. Peltonen, P. Pfaffi and A. Itkonen, Analyst, 1985, 110, 1173.

a.29

G.A. Stenmark, Anal. Chem., 1957, 29, 1367.

a.30

F.F. L’Ho, Anal. Chem., 1973, 45, 603.

CHN

carbon/hydrogen/nitrogen

a.31

F. Scholl, Atlas of Polymers and Polymer Analysis, 2nd Edition, Volume 3, Additives and Process Aids, Carl Hanser Verlag, 1981.

DEA

dielectric analysis

DMF

dimethylformamide

DMTA

dynamic mechanical thermal analysis

DPC

differential photocalorimetry

a.32

Toth, Muanyag es Gumi, 1968, 5, 9, 341.

a.33

T.E. Wallis, Practical Pharmacognosy, 6th Edition, J & A Churchill, London, 1953.

DRS

dielectric relaxation spectroscopy

DSC

differential scanning calorimetry

a.34

J. Haslam, H.A. Willis and D.C.M. Squirrell, Identification and Analysis of Plastics, 2nd Edition, Iliffe, 1972, 479.

Edax

energy dispersive analysis

EI

electron ionisation

ESI

electrospray ionisation

ESR

electron spin resonance spectroscopy

GC-MS

gas chromatography-mass spectrometry

GPC

gel permeation chromatography

HFIP

hexafluoroisopropanol

a.35

J. Haslam and R.V. Hill, Analyst, 1955, 80, 317.

a.36

P. Tittareli, T. Zerlia, A. Colli and G. Ferrari, Anal. Chem., 1983, 55, 220.

a.37

A.T. Hsu and A.G. Marshall, Anal. Chem., 1988, 60, 817.

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Analysis of Thermoset Materials, Precursors and Products

HPLC

high performance liquid chromatography

RI

refractive index

RIM

reaction injection moulding

i.d.

internal diameter

SEM

scanning electron microscope

ICP

inductively coupled plasma

SFC

supercritical fluid chromatography

IR

infrared spectroscopy

SIM

single ion monitoring

KE

kinetic energy

SIMS

secondary ion mass spectrometry

LAMMS

laser microprobe mass spectroscopy

SVNC

scanning vibrating needle curemeter

LC-MS

liquid chromatography-mass spectroscopy

TEM

transmission electron microscopy

Tg

glass transition temperature

LIMA

laser induced mass analysis

TGA

thermogravimetric analysis

MDSC

modulated DSC

THF

tetrahydrofuran

micro-TA

micro-thermal analysis

TLC

thin layer chromatography

Mn

number average molecular weight

TMA

thermal mechanical analysis

Mw

weight average molecular weight

TSC

thermally stimulated current

Mz

Z average molecular weight

UV

ultraviolet

NMR

nuclear magnetic resonance spectroscopy

XPS

X-ray photoelectron spectroscopy

XRD

X-ray diffraction

organic vapour analyser

XRF

X-ray fluorescence spectroscopy

OVA

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Analysis of Thermoset Materials, Precursors and Products

50

References and Abstracts

Abstracts from the Polymer Library Database Item 1 Polymer 44, No.5, 2003, p.1507-16 CONTROL OF VOLUME SHRINKAGE AND RESIDUAL STYRENE OF UNSATURATED POLYESTER RESINS CURED AT LOW TEMPERATURES. II. EFFECT OF COMONOMER Cao X; Lee L J Ohio,State University Integrated kinetics-morphology-property analysis, using differential scanning calorimetry, fourier transform infrared analysis, electron microscopy, shrinkage measurements and a series of Seemann composites resin infusion moulding processes (SCRIMP), were used to determine the effect of methyl methacrylate comonomer on the volume shrinkage and residual styrene content in an unsaturated polyester resin cured at low temperatures. Effects depend on the ratio of methyl methacrylate to styrene, with no effect on volume shrinkage and a decrease in residual styrene at low ratios but poor volume shrinkage control and substantial reductions in residual styrene at high ratios. 29 refs. USA

Accession no.882888 Item 2 Journal of Polymer Science: Polymer Physics Edition 41, No.4, 15th Feb.2003, p.418-28 MOLECULAR ORIENTATION OF RIGID-ROD POLYIMIDE FILMS CHARACTERIZED BY POLARIZED ATTENUATED TOTAL REFLECTION/FOURIER TRANSFORM INFRARED SPECTROSCOPY Matsuda A; Ando S Tokyo,Institute of Technology The variations in the molecular orientation of uniaxially drawn rigid-rod polyimide films were systematically characterised in all three dimensions with polarised ATR/ FTIR spectroscopy. The second-order orientation coefficients were deduced directly from the anisotropy in IR absorptions of particular bonds. With the draw ratio increasing, the state of the molecular orientation changed from being nearly planar to completely uniaxial via biaxial orientation and the degree of orientation was much larger than that of a semi-rigid polyimide having an ether linkage at the same draw ratio, which originated from the rigidrod structure. In addition, the imide planes were rotationally oriented to the out-of-plane direction of the film geometry. The relationship between the molecular chain orientation and the in-plane birefringence in the biaxial orientation state was re-examined. The intrinsic birefringence was estimated from biaxial orientation films to be 0.33 at a wavelength of 1307 nm. 37 refs. JAPAN

Accession no.882242

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Item 3 Polymer 43, No.26, 2002, p.7559-66 CHARACTERISTICS OF EPOXY RESIN CURED WITH IN SITU POLYMERIZED CURING AGENT Mimura K; Ito H Mitsubishi Electric Corp. Use of radical copolymerisation of vinyl monomers, Nphenylmaleimide and acetoxystyrene, in the viscosity reduction and cure of epoxy resins was studied by examination of the cured and curing resins using gel permeation chromatography, infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis and flexural tests. Curing of the epoxy resin occurred by reaction between the epoxy group of the epoxy resin and the ester group of the curing agent. Compared to the use of phenol resins in the curing system, a viscosity reduction of some 2000 times was achieved, but glass transition temperature of the cured material was increased by some 17 degrees centigrade. Flexural properties were similar for either cure system. 11 refs. JAPAN

Accession no.879450 Item 4 ACS Polymeric Materials: Science and Engineering. Spring Meeting. Volume 84. Proceedings of a conference held San Diego, Ca., 1st - 5th April 2001. Washington D.C.,ACS,Div.of Polymeric Materials Science & Engng., 2001, Paper 581, p.1051-3, 27cm,012 UV-CURING KINETICS STUDIES OF CYCLOALIPHATIC EPOXIDE USING REALTIME FT-IR SPECTROSCOPY Chen J; Soucek M D North Dakota State University (ACS,Div.of Polymeric Materials Science & Engng.) It was shown, using real time fourier transform infrared spectroscopic examination of the cationic curing of cycloaliphatic epoxides, that the curing speed and overall conversion are very dependent on the competition between proton transfer and the termination of cations, characteristics of water content and polyol. These in turn are dependent on the humidity, exposure time to an ultraviolet source, hydroxyl equivalent weight of polyol and R value. Results were illustrated graphically. 3 refs. USA

Accession no.879387 Item 5 ACS Polymeric Materials: Science and Engineering. Spring Meeting. Volume 84. Proceedings of a conference held San Diego, Ca., 1st - 5th April 2001.

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References and Abstracts

Washington D.C.,ACS,Div.of Polymeric Materials Science & Engng., 2001, Paper 557, p.1003-4, 27cm,012 ANALYSIS OF NETWORK STRUCTURE OF UV CURED ACRYLATES BY H NMR RELAXATION, C NMR SPECTROSCOPY AND DYNAMIC MECHANICAL EXPERIMENTS Litvinov V M; Dias A A DSM Research (ACS,Div.of Polymeric Materials Science & Engng.) The network structure of ultraviolet cured crosslinked polyacrylates was studied using mono- and di-functional acrylates as model systems. Nuclear magnetic resonance (NMR) spectroscopy and dynamic mechanical analysis (DMA) were used to analyse the system and it was shown that there was a heterogeneous distribution of network junctions and that good correlation was obtained between NMR and DMA in the indication of molecular weight between crosslinks. It was also observed that increasing the amount of monofunctional monomer resulted in a reduction in crosslink density. 2 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.879363 Item 6 Polyurethanes Conference 2002. Proceedings of a conference held Salt Lake City, Utah, 13th-16th Oct.2002. Arlington, Va., Alliances for the Polyurethanes Industry, 2002, Technical Session N - Fundamentals, Paper 7, p.624-35, 28 cm, 012 USE OF REAL-TIME FTIR TO CHARACTERIZE KINETICS OF AMINE CATALYSTS AND TO DEVELOP NEW GRADES FOR VARIOUS POLYURETHANE APPLICATIONS, INCLUDING LOW EMISSION CATALYSTS Chaffanjon P; Grisgby R A; Rister E L; Zimmerman R L Huntsman Corp. (American Plastics Council; Alliance for the Polyurethanes Industry) The use of in-situ Fourier transform infrared (FTIR) to follow PU reaction kinetics is studied using a heated probe matching the PU material temperature. The results obtained show that, although not giving access to concentration of formed chemical bonds, the technique is a unique tool to assess subtle differences in catalysts behaviour during actual PU formation, going beyond the currently used but restrictive characterisation of catalysts in terms of gelling, blowing or trimerisation grades. Examples of the use of the technique for the development of new amine catalysts are given for flexible and rigid foams. For flexible foams it is shown that FTIR characterises the gel potency in good agreement with the behaviour of known gel catalyst molecules and is therefore a good tool to develop new ones. Results comparing gel strength and foam emission data show that several

52

experimental grades have potential to be brought on the Jeffcat catalyst range. They also confirm the good performance of commercial low emission grades such as Jeffcat ZF10 as blow catalyst and Jeffcat ZR-50, DPA and Z-130 as gel catalysts. For rigid foams it is shown that FTIR provides good insight into the extent of trimer formation and is therefore the technique of choice to optimise catalyst blends for best fire performance and processing. 23 refs. USA

Accession no.878279 Item 7 Polymer 44, No.2, 2003, p.423-32 SELF-REFERENCING FLUORESCENCE SENSOR FOR MONITORING CONVERSION OF NONISOTHERMAL POLYMERIZATION AND NANOSCALE MIXING OF RESIN COMPONENTS Quirin J C; Torkelson J M Northwestern University The use of fluorescence probes to monitor the curing of commercial epoxy resins systems was explored, and a system described which altered in fluorescence by a factor of 5.9 for 80 percent conversion of the resin. The fluorescence probe used (dimethylaminonitrostilbene) was shown to operate independently of temperature, excitation intensity and monitoring geometry, and was self referencing. It was also shown that molecular scale mixing could be monitored by fluorescence non-radiative energy transfer between excited-state donor and acceptor chromophores. Overall stoichiometry of the resin system was shown to be capable of monitoring by the spectral shape of multiple directly excited chromophores, to a sensitivity of compositional changes of plus/minus one percent. 74 refs. USA

Accession no.878180 Item 8 Macromolecules 35, No.24, 19th Nov.2002, p.9044-8 UV, LUMINESCENCE, AND FTIR CHARACTERIZATION OF CURE REACTION IN BISPHENOL A DICYANATE ESTER RESIN Youzhi Eugene Xu; Chong Sook Paik Sung Connecticut,University UV, fluorescence, phosphorescence and IR spectroscopy techniques were used to monitor the cure reaction of bisphenol A dicyanate ester (BPADCY) resin. UV vis spectra and IR spectra results indicated that cyclotrimerisation of cyanate esters to form triazine rings was the main reaction during the curing of the resin. During the cure reaction, a very strong luminescence emission was found. The aromatically substituted

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References and Abstracts

cyanurates formed during the reaction were responsible for the observed emission and its trend in intensity. Insitu fluorescence characterisation showed similar results for the catalysed cure reaction with cobalt acetylacetonate/ nonylphenol as well as bisphenol A catalysed resin in comparison to purified BPADCY except for the faster rate in fluorescence spectral change. Phosphorescence emission appeared at 440 nm, which was about 20 nm longer than that of fluorescence. The phosphorescence lifetime remained relatively unchanged throughout the cure reaction. FTIR results for the BPADCY monomer indicated a linear relationship between the consumption rate of the cyanate ester groups and the formation rate of the substituted triazine rings. 13 refs.

an autocatalytic model with an apparent activation energy of 58 kJ/mol. The vitrification was analysed by TMDSC between 40 and 140C, using the modulus of the complex heat capacity. A mobility factor based on this last parameter was used to study the reaction step controlled by diffusion. The permittivity and loss factor were measured by DRS as a function of time between frequencies of 10 Hz and 100 kHz. The dipolar relaxation was correlated with the vitrification determined by TMDSC. Analysing the logarithm of the frequency against the degree of conversion enabled the molecular dynamics of the crosslinking reaction to be characterised up until the end of the vitrification of the system. 53 refs.

USA

EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.877352

Accession no.876734

Item 9 Polymer International 51, No.11, Nov.2002, p.1277-84 CHARACTERIZATION OF FREE VOLUME IN PARTICULATE-FILLED EPOXY RESIN BY MEANS OF DYNAMIC MECHANICAL ANALYSIS AND POSITRON ANNIHILATION LIFETIME SPECTROSCOPY Marzocca A J; Somoza A; Goyanes S N; Salgueiro W; Koenig P Buenos Aires,University; Buenos Aires,Comision de Investigaciones Cientificas de la Provincia; CONICET

Item 11 EURADH 2002. Adhesion ’02. Proceedings of a conference held Glasgow, 10th-13th Sept.2002. London. IOM Communications Ltd., 2002, Session 7; Chemistry and Rheology, Paper 5, p.125-8, 29cm, 012 COMBINING IR-ERAS AND SPECTRA CALCULATION FOR THE STUDY OF THE CURING REACTION IN ULTRA-THIN EPOXY FILMS ON METALS Wehlack C; Valeske B; Possart W Saarlandes,Universitat (Institute of Materials) Changes in the chemical structure of spin coated epoxy resin adhesive films on aluminium substrates were investigated using a combination of IR spectroscopy and reflection absorption spectroscopy during curing of the adhesive. The spectroscopic degree of epoxy conversion during curing of the ultra-thin films was quantitatively analysed and compared with that of bulk adhesive. 2 refs.

Dynamic mechanical analysis and positron annihilation lifetime spectroscopy (PALS) were used to study quartz powder-filled epoxy resins. The free volume of the composites decreased at low filler volume fraction compared with the unfilled sample, and increased at higher filler content. The behaviour was attributed to the presence of internal stresses produced during the cooling of the material. Dynamic mechanical analysis and PALS showed similar results for the dependence of free volume on the filler content of the composite. 35 refs. ARGENTINA

Accession no.877330 Item 10 Polymer 44, No.1, 2003, p.101-14 VITRIFICATION AND DIELECTRIC RELAXATION DURING THE ISOTHERMAL CURING OF AN EPOXY-AMINE RESIN Montserrat S; Roman F; Colomer P Catalunya,Universitat Politecnica The isothermal curing reaction of an epoxy resin (based on bisphenol A diglycidyl ether) cured with a diamine based on 4,4'-diamino-3,3'-dimethyldicyclohexylmethane was studied using dielectric relaxation spectrocopy (DRS), conventional DSC and temperature modulated DSC (TMDSC). The chemical kinetics corresponded to

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EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; UK; WESTERN EUROPE

Accession no.876569 Item 12 EURADH 2002. Adhesion ’02. Proceedings of a conference held Glasgow, 10th-13th Sept.2002. London. IOM Communications Ltd., 2002, Session 7; Chemistry and Rheology, Paper 3, p.117-20, 29cm, 012 REACTIVE INTERACTIONS BETWEEN NATIVE ALUMINIUM SURFACES AND EPOXY BASED ADHESIVES Wilken R; Dieckhoff S Fraunhofer-Institut fuer Fertigungstechnik und Ang.Materialforschung (Institute of Materials) Thin films of diglycidyl ether of Bisphenol A (DGEBA) and diethylene triamine (DETA) were deposited in-situ on aluminium substrates by vapour deposition and the aluminium substrates and DGEBA and DETA layers on the aluminium substrates characterised by X-ray

53

References and Abstracts

photoelectron spectroscopy. It was found that DGEBA did not interact with the aluminium surface while DETA was immediately chemisorbed onto the aluminium surface. No reaction between DGEBA and DETA was observed when DGEBA was deposited on the DETA modified aluminium surface. 2 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.876567 Item 13 Analytical Chemistry 74, No.21, 1st Nov.2002, p.5501-6 HELICAL SORBENT FOR FAST SORPTION AND DESORPTION IN SOLID-PHASE MICROEXTRACTION-GAS CHROMATOGRAPHIC ANALYSIS Ciucanu I Timisoara,West University The development of a new technique for solid-phase microextraction of analytes, which uses a PDMS helical solid sorbent, is described. The technique, which is solvent-free in thermal desorption, reduces the time of sorption and desorption in dynamic extraction by generating a rotational flow of analytes and turbulence on the surface of the sorbent. The extraction time with the PDMS helical sorbent is shown to be much faster that that with a PDMS silica rod. 26 refs. EASTERN EUROPE; RUMANIA

Accession no.875930 Item 14 Journal of Polymer Science: Polymer Chemistry Edition 40, No.23, 1st Dec.2002, p.4236-44 ULTRAVIOLET CURING OF ACRYLIC SYSTEMS: REAL TIME FOURIER TRANSFORM INFRARED, MECHANICAL, AND FLUORESCENCE STUDIES Peinado C; Salvador E F; Alonso A; Corrales T; Baselga J; Catalina F CSIC; Madrid,Universidad Carlos III The UV curing of an acrylic adhesive was studied with two different initiators (2-benzyl-2-N,N-dimethylamino1-(4-morpholinophenyl)-1-butanone (DBMP) or bis(2,4,6-trimethylbenzoyl)phenyl phosphine oxide (TMBAPO)). Real time FTIR was used to measure the acrylate double bond conversion at different irradiation times and the changes in fluorescence intensity were also measured in real time. The polymerisation rate depended on the square root of the absorbed light intensity when DMBP was used as the photoinitiator, whereas primary radical termination was observed when TMBAPO was used. The fluorescence emission changes of different fluorescent probes during UV curing also showed different behaviours which depended on the nature of the photoinitiator. The results were discussed. 19 refs.

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EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.875050 Item 15 Shawbury, Rapra Technology Ltd., 2002, pp.144, 29 cm, Rapra Review Report 152, vol.13, No.8, 2002. NALOAN NATURAL AND WOOD FIBRE REINFORCEMENT IN POLYMERS Bledzki A K; Sperber V E; Faruk O Kassel,Universitat Edited by: Humphreys S (Rapra Technology Ltd.) Rapra.Review Report No.152 The use of natural and wood fibre reinforcements in polymers is reviewed with respect to types, properties, surface treatment of fibres, processing, properties of composites, and applications. End-use applications examined, include the automotive industry, building industry, furniture and panels and aerospace applications. Some statistics are included for the consumption of natural fibres in Europe by the automotive industry 1996-2010. 485 refs. NORTH AMERICA; WESTERN EUROPE

Accession no.874532 Item 16 Shawbury, Rapra Technology Ltd., 2002, pp.124, 29 cm, 1742 THERMOSET RESINS. MARKET REPORT Forsdyke K L; Starr T F Rapra Technology Ltd. This study examines the different types of thermosets, outlines their respective methods of manufacture and conversion into finished products, gives details of applications, and quantifies their current and forecasts their future market status. Emphasis is placed on key developments taking place or significant consumption trends. Other chapters are devoted to company profiles, standards and legislation, environmental considerations and recycling. WORLD

Accession no.874530 Item 17 Shawbury, Rapra Technology Ltd., 2002, pp.146, 29 cm, Rapra Review Report, No. 149, vol. 13, No.5, 2002. NALOAN ANALYSIS OF PLASTICS Forrest M J Rapra Technology Ltd. Edited by: Humphreys S (Rapra Technology Ltd.) Rapra.Review Rept. No.149 This review aims to present an introduction to the techniques and methods which are used to characterise

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References and Abstracts

and carry out quality control work on plastics, to investigate the failure of plastic products, and to deformulate plastic compounds. Consideration is given to analytical techniques including wet chemistry techniques, spectroscopic, chromatographic, thermal, elemental, and microscopy techniques. This section is followed by a review of methods used to determine the molecular weight and microstructure of polymers, methods for the determination of polymer type, techniques for the determination of the plasticiser and filler in a plastic compound, methods for the determination of type and levels of stabilisers in a plastic compound, and for the determination of functional additives. Migration and residual monomer tests for the analysis of plastics for food contact use are discussed, and methods for the determination of stabilisers used in PVC. Analysis methods for laminates and fibres, surface analysis, and failure diagnosis are included. The latter includes contamination problems, odour and emission, and environmental stress cracking. 422 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.872185 Item 18 Polymer Testing 22, No.1, 2003, p.51-6 DETERMINATION OF THE EPOXIDE EQUIVALENT WEIGHT OF EPOXY RESINS BASED ON DIGLYCIDYL ETHER OF BISPHENOL A Garcia F G; Soares B G Rio de Janeiro,Universidade Federal A methodology for the determination of epoxide equivalent weights (EEW) in liquid epoxy resins based on the diglycidyl ether of bisphenol A (DGEBA) using proton nuclear magnetic resonance (1H-NMR) spectroscopy is described. The data obtained are in good agreement to those obtained from the classical titration procedure with HBr in glacial acetic acid. The 1H-NMR method constitutes an alternative for the characterisation of epoxy resin, since it is rapid and free of interfering chemical reagents. 9 refs. BRAZIL

Accession no.872000 Item 19 Polymer Preprints. Volume 41, Number 1. Proceedings of a conference held San Francisco, Ca., March 2000.. Washington D.C., ACS,Div.of Polymer Chemistry, 2000, p.667-668, 28cm, 012 MASS SPECTRAL ANALYSIS OF LOWTEMPERATURE PYROLYSIS PRODUCTS FROM POLY(TETRAHYDROFURAN) Lattimer R P Goodrich B.F.,Co. (ACS,Div.of Polymer Chemistry)

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Recent studies have shown that MALDI-MS is a very useful method for analysing pyrolysis products from polar polymers. MALDI has been used to examine pyrolysates from polypropylene glycol, PEG, polybutylene adipate and a segmented PU. MALDI-MS has been found to be advantageous in that much higher molecular weight pyrolysates can be studied than is possible using more traditional mass spectral methods (such as GC/MS). There has been interest in the thermal degradation of PUs, and PTHF is a common soft segment used in urethane manufacture. The low temperature decomposition of dihydroxyl-terminated PTHF is investigated, using MALDI-MS and CI-MS to analyse the pyrolysates. Chemical structures for the oligomeric products are elucidated in detail, and a free radical degradation mechanism is proposed to explain the formation of pyrolysates. 10 refs. USA

Accession no.870564 Item 20 Polymer Preprints. Volume 41, Number 1. Proceedings of a conference held San Franscisco, Ca., March 2000.. Washington D.C., ACS,Div. of Polymer Chemistry, 2000, p.361-2, 28cm, 012 ESR ANALYSIS OF PHOTO-INDUCED RADICALS IN POLYURETHANE CLEARCOATS Ying He; Jean Y C; Sandreczki T C Missouri-Kansas City,University (ACS,Div.of Polymer Chemistry) ESR was used to study early-stage free radicals generated by UV light at 77K during the photodegradation of polyurethanes. Results obtained for separate components of a PU clearcoat showed that either adipic acid or a secondary radical from 1,1,1-trimethylolpropane was the component that produced the 5-line ESR signal in the PU clearcoat. Phthalic acid could account for the unresolved single broad centre line in the spectrum. 4 refs. USA

Accession no.869176 Item 21 Polymer Preprints. Volume 41, Number 1. Proceedings of a conference held San Francisco, Ca., March 2000. Washington D.C., ACS,Div.of Polymer Chemistry, 2000, p.22-3, 28cm, 012 MODIFIED POLYSULFIDES: THEIR PREPARATION, CHARACTERIZATION, PHOTOACTIVITY AND POTENTIAL APPLICATIONS Caddy M; Kemp T J Warwick,University (ACS,Div.of Polymer Chemistry) Acylation of liquid polysulphides was carried out, resulting in a photocrosslinkable product which forms a solid elastomeric material with good adhesion to a

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References and Abstracts

substrate. Photopolymerisation was monitored using nuclear magnetic resonance spectroscopy. also used in characterising the polysulphides were mass spectroscopy, gel permeation chromatography and viscometry. Potential uses in surface coatings are foreseen. 4 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.868862 Item 22 Polymer 43, No.11, 2002, p.3381-6 MULTIVARIATE ANALYSIS OF SPECTRA OF CYANATE ESTER/BISMALEIMIDE BLENDS AND CORRELATIONS WITH PROPERTIES Hamerton I; Herman H; Mydhar A K; Chaplin A; Shaw S J Surrey,University; UK,Defence Evaluation & Research Agency Multivariate analysis of cured cyanate ester/bismaleimide blends subjected to accelerated ageing tests by immersing in water at temperatures up to 70C showed that nearinfrared spectroscopy of virgin materials could predict dynamic mechanical thermal analysis results and provide correlations with thermogravimetric analysis. This suggested a rapid screening method for a range of materials. 6 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.868767 Item 23 Macromolecular Symposia No.187, 2002, p.861-71 QUANTITIVE USE OF ULTRAVIOLET SPECTROSCOPY TO CALCULATE THE EFFECTIVE IRRADIATION DOSAGE DURING WEATHERING Croll S; Skaja A North Dakota State University The UV absorbance of a PU coating shows typical yellowing that increases with exposure period. All effective dosage is calculated from the solar spectrum, the quantum yield for the degradation process and the UV absorption. Assuming a constant quantum yield, there is a clear acceleration of the absorption of damaging radiation because the UV absorption increases with exposure. This non-linear relationship offers possibilities on how to estimate a service lifetime. In addition, the yellowing can be analysed as an ‘Urbach’ tail which is usually attributed to structural disorder that introduces energy levels between the ground and excited electronic states. 21 refs. USA

Accession no.867980

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Item 24 Macromolecular Symposia No.187, 2002, p.845-52 DURABILITY PREDICTION OF P-URETHANE CLEARCOATS USING INFRARED P(HOTO) A(COUSTIC) S(PECTROSCOPY) van Der Ven L G J; Leuverink R Akzo Nobel Coatings Research The durability of topcoats is dependent on a large number of factors such as polymer composition, stabilisation package and the conditions during the weathering process. For obvious reasons, prediction of the long-term durability of coatings is very important. The rate-determining factor for the degradation of PU coatings is photo-oxidation. The photo-oxidation rate is controlled by the polymer structure but also stabilisers, such as HALS, have a large influence. The prediction of the durability of clearcoats is based on tracing of the photooxidation rate and of the HALS longevity during exposure. The photo-oxidation rate is measured using FTIR-PAS. The results show that degradation can be detected much earlier compared with classic methods like gloss loss. Moreover, detection of differences between systems after short exposure times, as well as prediction of the long-term durability, is possible. 4 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.867978 Item 25 Polymer Preprints. Volume 42. Number 1. Spring 2001. Papers presented at the ACS Meeting held San Diego, Ca., 1st-5th April 2001. Washington, D.C., ACS, Div.of Polymer Chemistry, 2001, p.328, 28 cm, 012 REAL-TIME MELAMINE FORMALDEHYDE REACTION MONITORING USING IN-SITU FTIR SPECTROSCOPY Pavlosky M; Ferwerda R; Scheepers M; Nusselder J J ASI Applied Systems; DSM Melamine (ACS,Div.of Polymer Chemistry) The characteristics and behaviour of melamine formaldehyde resins are strongly related to their chemical structure. While analytical tools are currently available for investigating the composition of these resins, many require sample extraction and preparation prior to analysis and long delays are common. Recent advances in technology for in-situ composition monitoring now provide the advantage of monitoring the reactions under actual reaction conditions. In-situ FTIR monitoring is an ideal method for tracking chemical composition changes. The concentration of key reaction species can be followed directly using their isolated infrared bands or established quantitative methods. Modern in-situ FTIR technology can thus provide real-time information on the reaction progress and endpoints (so-called cloud point). From the experiments described, the possibilities of FTIR

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References and Abstracts

spectroscopy for monitoring the key melamine formaldehyde functional groups in real-time processes are discussed. The combination of real-time technologies is said to make it possible to follow the key species during the reaction. Due to the overlap of the spectral features of characteristic bands processing techniques, such as second derivative or factor analysis (ConcIRT), are necessary to describe the concentration trends. In practice, it is of extreme importance to be able to accurately control the experimental parameters between slightly different reaction conditions. FTIR spectroscopy, characterised by its high sensitivity, can still detect small differences in concentrations of the key MF species for different reaction conditions. In the future, this technology can be further explored for in-situ process control. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; USA; WESTERN EUROPE

Accession no.866679 Item 26 Chinese Journal of Polymer Science 20, No.5, Sept.2002, p.419-23 IMPEDANCE CHARACTERISTICS OF POLYFURAN FILMS Li L; Wan X-B; Xue G Nanjing,University Electrochemical impedance spectroscopy (EIS) is first used for the characterisation of polyfuran (PFu) films been formed electrochemically on an electrode. The polyfuran is measured in high oxidation state intermediate oxidation state and reduction state, respectively. As the oxidation level is increased, the ionic conductivity of PFu/BF4 increases. Impedance studies on PFu show that the anion BF4- appears to be mobile with a high diffusion coefficient of approximately 10-8 sq.cm s-1. 24 refs. CHINA

Accession no.866553 Item 27 Macromolecular Symposia Vol.184, 2002, p.249-60 FT-NIR MONITORING OF A SCATTERING POLYURETHANE MANUFACTURED BY REACTION INJECTION MOLDING (RIM): UNIVARIATE AND MULTIVARIATE ANALYSIS VERSUS KINETIC PREDICTIONS Dupuy J; Benali S; Maazouz A; Lachenal G; Bertrand D INSA; Laboratoire des materiaux plastics et biomateriaux; Nantes,unite de sensometrie et de chimiometrie The curing of a PU formulation was monitored in-situ during reaction injection moulding using Fourier transform near-IR spectroscopy in the transmission mode. The degree of conversion was calculated using univariate and multivariate analyses of the transmission spectra.

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Conversions calculated by Principal Component Analysis were found to be in very good agreement with those predicted using the Beer-Lambert law and simulated conversions based on a kinetic model. 27 refs. (14th European Symposium on Polymer Spectroscopy, Dresden, 2nd-5th Sept., 2001, Germany) EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.866445 Item 28 Macromolecular Symposia Vol.184, 2002, p.79-97 REAL-TIME FTIR-ATR SPECTROSCOPY OF PHOTOPOLYMERIZATION REACTIONS Scherzer T Institut fuer Oberflaechenmodifizierung eV The results are reported of investigations into free-radical photopolymerisations of acrylate-based systems. Aspects covered include the effect of temperature on the kinetics of polymerisation and characterisation of the depth profile of the conversion of double bonds, photoinitiator-free photopolymerisation of acrylates exposed to short wavelength UV radiation and simulations of irradiation schemes in UV curing processes. 39 refs. (14th European Symposium on Polymer Spectroscopy, Dresden, 2nd-5th Sept., 2001, Germany) EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.866433 Item 29 ANTEC 2002. Proceedings of the 60th SPE Annual Technical Conference held San Francisco, Ca., 5th-9th May 2002. Brookfield, Ct., SPE, 2002, Paper , Session , pp.9, CDROM, 012 REVERSE ENGINEERING OF POLYMERIC MATERIALS Bart J C J DSM Research (SPE) The procedures used by the major industrial companies operating in the plastics field to separate and analyse the constituents in plastics and rubber formulations are briefly reviewed and tabulated. 31 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.863898 Item 30 Applied Spectroscopy 56, No.6, June 2002, p.737-43 COMPARATIVE STUDY OF AN ANISOTROPIC POLYMER LAYER BY INFRARED SPECTROSCOPIC TECHNIQUES

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Hinrichs K; Tsankov D; Korte E H; Roeseler A; Sahre K; Eichhorn K-J Berlin,Institute of Spectrochemistry & Applied Spectroscopy; Dresden,Institute of Polymer Research The anisotropic optical properties of a thin film of polyimide were investigated over the spectral range of 4,000 to 500 cm/1 using infrared spectroscopic ellipsometry, reflection absorption IR spectroscopy, IR transmission spectroscopy and best-fit calculations. A comparison was made of the experimental spectra with anisotropic uniaxial optical layer model predictions and the suitability of the best-fit calculations for evaluating ellipsometry, transmission and polarised reflection spectra demonstrated. 30 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.860276 Item 31 Macromolecules 35, No.14, 2nd July 2002, p.5500-7 TWO-DIMENSIONAL(2D) ATR-FTIR SPECTROSCOPIC STUDY ON WATER DIFFUSION IN CURED EPOXY RESINS Mojun Liu; Peiyi Wu; Yifu Ding; Gang Chen; Shanjun Li Fudan,University An experimental approach based on time-resolved 2D ATR-FTIR spectroscopy was used to study water diffusion behaviour of novolac epoxy resins cured with novolac resin and novolac acetate resin. The diffusion coefficients calculated by a non-linear curve fitting were quite consistent with the results of gravimetric analysis. In 2DIR spectra, the splitting of the water OH vibration band at 2800 to 3700 and 1500 to 1800/cm showed that there were two different states of water in epoxy resin networks, in which one could be confined into free volume (microvoids) or molecularly dispersed with less hydrogenbonding (bulk dissolved), while the other could be attributed to bound water forming strong hydrogenbonding with hydrophilic groups of epoxy resin networks. The sequential order of intensity changes of the two water bands showed that, in the process of water diffusion into epoxy resin networks, water molecules first bound with specific hydrophilic groups as bound water and then diffused into free volume or molecularly dispersed with less hydrogen-bonding. 35 refs. CHINA

Accession no.860077 Item 32 Journal of Applied Polymer Science 85, No.5, 1st Aug.2002, p.950-6 STUDY ON THE PHASE SEPARATION OF THERMOPLASTIC-MODIFIED EPOXY SYSTEMS BY TIME-RESOLVED SMALL-

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ANGLE LASER LIGHT SCATTERING Qiang Zheng; Kuitian Tan; Mao Peng; Yi Pan Hangzhou,Zhejiang University Time-resolved small-angle laser light scattering (SALLS) was used to study reaction induced phase-separation of an epoxy (E-51) system modified by thermoplastics, i.e. polyetherimide (PEI) and polycarbonate (PC), cured isothermally with 4,4'-diaminodiphenylsulphone (DDS) at different temperatures. It was found that competition between the curing reaction and phase separation controlled the morphology evolution of the E-51 system. Analysis of the scatter pattern evolution and the cocontinuous morphology by optical microscopy showed that phase separation in these systems involved a spinodal decomposition mechanism. The determining factors for the domain size and phase separation in these epoxy systems were thought to be the curing temperatures and compositions. 24 refs. CHINA

Accession no.859711 Item 33 Journal of Applied Polymer Science 85, No.7, 15th Aug.2002, p.1465-8 SOLID-STATE NUCLEAR MAGNETIC RESONANCE STUDY OF POLYURETHANE/ NATURAL FIBRES COMPOSITES Tavares M I B; Mothe c G; Araujo C R Rio de Janeiro,Cidade Universitaria Fibre-reinforced plastics (FRP) are prepared with sisal and sugarcane waste material. Composites of these fibres with PUs are obtained by processing these materials in a Haake plastograph, and their homogeneity is characterised by nuclear magnetic resonance measurements. The results are discussed in terms of composites interaction, homogeneity and compatibility. 10 refs. BRAZIL

Accession no.858753 Item 34 Italia Imballaggio No.4, April 2002, p.214/22 MIGRATION UNDER CONTROL Rossi M; Neri Mari M; Bucaria F; Borsani M Sapici SpA A specific method of analysis has been developed by Sapici, a manufacturer of PU adhesives for flexible packaging, to determine primary aromatic amines migration by way of GC/MS. Primary aromatic amines (PAA) may be present in packaging materials intended to come in contact with foodstuffs. PAAs can be generated by reaction between free aromatic isocyanate monomers and water present in foodstuffs. Regulations regarding migration of PAAs from packaging are outlined and the methods of analysis based on the photometric method and the GC/MS method are described.

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References and Abstracts

EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.857687 Item 35 Journal of Adhesion 78, No.4, 2002, p.297-312 MOISTURE-CURING KINETICS OF ISOCYANATE PREPOLYMER ADHESIVES Lepene B S; Long T E; Meyer A; Kranbuehl D E Virginia,Polytechnic Institute & State University; William & Mary College An investigation was carried out into the use of in-situ FTIR spectroscopy for monitoring the chemistry of the kinetics of polymerisation between isocyanate-terminated urethane prepolymers and atmospheric moisture. Changes in the mobility of ions in the reaction medium were followed by means of frequency dependent dielectric sensing with a thin, planar sensor. A good correlation was established between frequency dependent dielectric sensing changes in ionic mobility and FTIR spectroscopic monitoring of the isocyanate during moisture curing. 19 refs. USA

Accession no.857245 Item 36 Journal of Polymer Science: Polymer Physics Edition 40, No.10, 15th May 2002, p.922-38 PROBING THE MOLECULAR INTERACTIONS IN THE DIFFUSION OF WATER THROUGH EPOXY AND EPOXY-BISMALEIMIDE NETWORKS Musto P; Ragosta G; Scarinzi G; Mascia L Naples,Institute of Research & Technology of Plastics Materials; Loughborough,University The molecular interactions between absorbed water molecules and networks based on a tetrafunctional epoxy resin were studied with the aid of FTIR and near-infrared spectroscopy. One network was a typical formulation containing 4,4'-diamino diphenylsulphone as a hardener and the other was a modified resin containing 4,4'bismaleimide-diphenylmethane (BMI) as a coreactive monomer. The spectroscopic results confirmed the presence of mobile water localised in network defects (microvoids) which did not react with the networks and water molecules hydrogen bonded to the networks. The fraction of bound water in the BMI system was less than in the unmodified epoxy resin, which was relevant since the bound water was mostly responsible for network plastification and consequent deterioration of mechanical performance. Gravimetric sorption measurements and time-resolved FTIR were used to study water diffusion, and indicated that the presence of BMI decreased the equilibrium water content, increased diffusivity, and lowered the diffusion activation energy. A dual-mode

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diffusion model was found to be suitable for accurate description of mass transport in both systems. The model simulation results provided a means for estimating the ratio of free to bound water, and this ratio was in good agreement with the spectroscopy results. 32 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; UK; WESTERN EUROPE

Accession no.855553 Item 37 Journal of Polymers and the Environment 8, No.4, Oct. 2000, p.167-74 SENSITIVE ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY METHOD FOR DETECTION OF POLYIMIDE DEGRADATION BY MICROORGANISMS Gu J-G; Cheng S-P; Liu J; Gu J-D Shenyang,Agricultural University; Nanjing,University; Beijing,University of Aeronautics & Astronautics; Hong Kong,University An electrochemical impedance spectroscopy method was evaluated for monitoring the microbial degradation of polyimides for electronic packaging. A mixed culture of fungi isolated from degraded polyimides was used as the microbial inoculum and scanning electron microscopy was employed to examine fungi growing on the surface of the inoculated polyimides. The data from the microscopic analysis was utilised to further support the relationship between changes in the impedance spectra and microbial degradation of the polyimide. 30 refs. CHINA; HONG KONG

Accession no.853552 Item 38 International Polymer Science and Technology 29, No.4, 2002, p.T/69-77 USE OF SOLVATOCHROMISM FOR SPECTROPHOTOMETRIC DETERMINATION OF MALEIMIDES Isaev R N; Ishkov A V The characterisation of polymeric materials based on maleimides is discussed with reference to the use of solvatochromism. Methods were developed for the spectrophotometric determination of mono- and dimaleimides using various organic solvents. Results are published of studies of mainly N-phenyl-substituted monomaleimides: N-phenylmaleimide, N-o- and BN-ptolylmaleimides, N-p-nitrophenylmaleimide, N-piodophenylmaleimide, N-1-naphthylmaleimide, and also N-2-pyridylmaleimide, and the dimaleimides: hexamethylenedimaleimide,m-phenylenedimaleimide, 4,4'-bismaleimidediphenylmethane. 47 refs. (Article translated from Plasticheskie Massy, No.7, 2001, pp.30). RUSSIA

Accession no.853074

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Item 39 Polymer 43, No.8, 2002, p.239-43 INFLUENCE OF THE TEMPERATURE ON THE FORMATION OF A PHENOLIC RESOL RESIN CATALYZED WITH AMINE Astarloa Aierbe G; Echeverria J M; Riccardi C C; Mondragon I Pais Vasco,Universidad; Bakelite-Iberica; Mar del Plata,Universidad Nacional Liquid chromatography and 13C nuclear magnetic resonance spectroscopy were used to study the influence of condensation temperature on phenolic resol resin prepolymer formation. Four resols were prepared at temperatures of 60, 80, and 95 C, and also at the reflux temperature (98-102 C), using a formaldehyde:phenol molar ratio of 1.8, an initial pH of 8.0, and triethylamine catalyst. With increasing condensation temperature, the reactant consumption rates and initial addition products increased, whilst the condensation times decreased. The prepolymers synthesised at refluxing temperatures exhibited preferential formaldehyde addition onto ortho positions. A variety of bonds connecting phenolic rings were observed. The residual phenol and formaldehyde, and the number of free unreacted ortho and para positions, decreased with increasing temperature. 19 refs. ARGENTINA; EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.851396 Item 40 Polymer International 50,No.10,Sept.2001,p1150-5 URETHANES AND POLYURETHANES BASED ON OXYPROPYLATED CORK: PART I. APPRAISAL AND REACTIVITY OF PRODUCTS Evtioguina M; Gandini A; Neto C P; Belgacem N M Aveiro,Universidade; INPG To assess the possible utilisation of oxypropylated cork macromonomers in the preparation of polymeric materials, the kinetic behaviour of cork based polyols in solution with various isocyanates was studied and products characterised. Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and differential scanning calorimetry was used for analysis. The products arising from the oxypropylation of cork reacted without difficulty with isocyanates and exhibited regular kinetic behaviour. It was concluded that these liquid polyols, as a renewable resource, were potentially suitable macromonomers for polyurethane formulations and further work was justified using undiluted monomers and commercial polyisocyanates. Complete details of the experimental procedures and chemical reactions observed are given and the results fully discussed. 12 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; PORTUGAL; WESTERN EUROPE

Accession no.849083

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Item 41 Polymer International 50,No.10,Sept.2001,p1073-81 IN SITU FT-IR AND DSC INVESTIGATION ON THE CURE REACTION OF DICYANATE/ DIEPOXIDE/DIAMINE SYSTEM Lin R H; Hsu J H Taiwan,National Kaohsiung University of Applied Science Work was directed towards the improving the dielectric loss and moisture absorption properties of epoxy resin systems by using an aromatic dicyanate ester as a latent catalyst to cure bisphenol based epoxy resins. The cure reactions were studied using Fourier transform infrared spectroscopy and differential scanning calorimetry in dynamic scanning mode. It was concluded that four principal reaction mechanisms were present with the cyanate ester system and there were two distinct exotherm peaks. The secondary epoxy-amine reaction forming tertiary amines proved inconsequential in this curing system due to the negative substitution effect of the amine compound. Details of the experimental and test procedures are given with full discussion of the results. 32 refs. TAIWAN

Accession no.849072 Item 42 Macromolecules 35, No.3, 29th Jan.2002, p.883-8 FLUORESCENCE AND IR CHARACTERIZATION OF CURE IN POLYUREA, POLYURETHANE, AND POLYURETHANE-UREA Shi-Kwn Wang; Chong Sook Paik Sung Connecticut,University Fluorescence and IR spectroscopic methods were used to characterise the cure reaction in polyurea, PU and polyurethane-urea (PUU), based on results which had been obtained previously using model compounds. The PUU was prepared from MDI, 3,5-diethyltoluenediamine (chain extender) and a hydroxyl-terminated poly(propylene oxide-ethylene oxide) copolymer. Using the IR bands previously identified using the model compounds, the fluorescence behaviour during the curing process of PUU was interpreted. 13 refs. USA

Accession no.848195 Item 43 Journal of Materials Science Letters 20, No.23, 1st Dec.2001, p.2101-4 EVALUATION IN ‘TRANSPARENCY’ OF GLASS PARTICLE-DISPERSED OPTICAL COMPOSITES BY PICO-SECOND ORDER PULSE PROFILE

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References and Abstracts

Matsumura K; Kagawa Y Tokyo,University

Fuji Silysia Chemical Ltd.; Tokai,Technical Center Foundation; Nagoya,Institute of Technology; Procter & Gamble Co.

The application of the change of pico-second order light pulse profile for the evaluation of light transparency in glass particle-dispersed epoxy resin matrix composites. The experimental results demonstrated that change of the pico-second order pulsed light profile appeared as a decrease of the peak intensity of transmitted pulse and a broadening of the profile (increase of full width at half maximum of the pulse width). The optical transparency of the composite was evaluated above the changes. It was concluded that this procedure was effective for evaluation of optical transparency of a bulk material, which was difficult to achieve by the conventional light transmittance measurement. 18 refs.

JAPAN; USA

JAPAN

Accession no.845493

Accession no.847502 Item 44 Journal of Applied Polymer Science 83, No.8, 22nd Feb.2002, p.1635-42 QUANTITATIVE DETERMINATION OF THE DISTRIBUTION OF FREE HYDROXYLIC AND CARBOXYLIC GROUPS IN UNSATURATED POLYESTER AND ALKYD RESINS BY PHOSPHORUS-31-NMR SPECTROSCOPY Spyros A Crete,University The hydroxyl and carboxyl contents of unsaturated polyester and alkyd resins were determined quantitatively and simultaneously through the derivatisation of the labile -OH and -COOH protons with 2-chloro-4,4,5,5tetramethyldioxaphospholane and the detection of their phosphitylated derivatives with phosphorus-31 NMR spectroscopy. This technique was superior to titration methods because it was able to distinguish between primary and secondary hydroxyl groups, to identify individual alcohols and acids present, to measure the amount of free fatty acids in oil-modified alkyds, and to give lower limits for the number-average molecular weight of the resins and exact values for linear polyesters. This technique also has the big advantage that it can be used to study resins as prepared by the manufacturer in their final product form. 12 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GREECE; WESTERN EUROPE

Accession no.845522 Item 45 Macromolecules 35, No.1, 1st Jan.2002, p.92-6 TWO-DIMENSIONAL CORRELATION GEL PERMEATION CHROMATOGRAPHY STUDY OF OCTYLTRIETHOXYSILANE SOL-GEL POLYMERIZATION PROCESS Izawa K; Ogasawara T; Masuda H; Okabayashi H; Noda I

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The two-dimensional correlation GPC technique was described. It was used to study the sol-gel polymerisation process of octyltriethoxysilane catalysed by 1.0 M HCl water and provided a detailed description of the process in terms of the relationship between the monomeric and polymeric precursors. GPC traces were collected sequentially at different sampling points during the reaction and were converted into two-dimensional correlation maps. The two-dimensional GPC maps created by the correlation analysis directly reflected the reaction mechanism. 17 refs.

Item 46 Journal of Applied Polymer Science 82, No.11, 9th Dec.2001, p.2607-15 FLUORESCENCE METHOD FOR MONITORING ISOTHERMAL CURING AND SHELF LIFE OF AN EPOXY-ANHYDRIDE SYSTEM Vatanparast R; Li S; Lemmetyinen H Tampere,University of Technology A fluorescence technique, using seven fluorescent probes, was evaluated for the monitoring of the curing and shelf life of an epoxy resin. The probes fluorescence emission bands exhibited blue shifts, attributed to microviscosity and micropolarity changes. An intensity ratio method, using the ratios of the lowest and highest intensity changes in the emission bands, was used to establish the degree of isothermal curing. The method was also suitable for the study of pre-curing, the shelf life of the epoxy, and for the determination of the kinetics of various monomer and resin formulations under constant curing conditions. 52 refs. EUROPEAN UNION; FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.844707 Item 47 Adhasion Kleben & Dichten 45, No.12, 2001, p.34-8 German NON-DESTRUCTIVE NUCLEAR MAGNETIC RESONANCE CONTACT TECHNIQUE EXAMPLES AND POSSIBILITIES Hartwig A; Wolter B Fraunhofer-Institut fuer Ang.Materialforschung; Bundesministerium fuer Wirtschaft; DECHEMA On page 25 of the November 2001 issue of Adhaesion, Kleben & Dichten, the nuclear magnetic resonance contact technique was introduced as a new sort of method for non-destructive characterisation of polymers. This article uses examples from the area of epoxy resins and

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thick-layer bondings to give an impression of typical, potential applications for this new non-destructive testing method. 2 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.844288 Item 48 Polymer 43, No.4, 2002, p.1051-9 NMR STUDY OF THE GAMMA RADIOLYSIS OF POLYDIMETHYL SILOXANE UNDER VACUUM AT 303 K Hill D J T; Preston C M L; Whittaker A K Queensland,University The structural changes which occur on the gammaradiolysis of polydimethyl siloxane (PDMS) under vacuum at 303 K are investigated using 29 Si and 13C NMR. New structural units consistent with main chain scission and crosslinking through both H-linking and Ylinking reactions are identified. The results obtained at various absorbed doses are used to calculate the G-values for scission and crosslinking. G-values, for scission of G(S) = 1.3 + or -0.2, for H-linking of G(D CH2-R) = 0.34 + or -0.02 and for Y-linking of G(Y) = 1.70 + or 0.09 are obtained for radiolysis under vacuum at 303 K. Thus crosslinking predominates over scission for radiolysis of PDMS under these conditions, and, by contrast with previous studies, Y-links are shown to be the predominant form of crosslinks. 35 refs. AUSTRALIA

Accession no.843613 Item 49 1996 Plastic Laminates Symposium. Conference proceedings. Atlanta, Ga., 19th-22nd August 1996, Paper 16 ANALYSIS OF MF RESINS Aarts V M L J; Scheepers M L; Brandts P M DSM Research (TAPPI) The influence of condensation variables, such as F/M ratio, pH and condensation temperature, on the chemical structure of liquid MF resins, is studied with the aid of high resolution 13C solid and liquid NMR, HPLC and Raman spectroscopy. These techniques can be used to obtain qualitative as well as quantitative information about the chemical composition of MF resins. Where necessary, these analytical tools are further developed. The degree of condensation of MF resins can be studied by quantitatively measuring the amount of water released, via 1H NMR, or by measuring the total number of bridges via 13C NMR. Quantitative 13C NMR measurements reveal a strong relation between water tolerance and the number of ether and methylene bridges in the MF resin. This relation can be used to estimate ether and methylene

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bridge concentrations in MF resins with a known F/M ratio, solids content and condensation pH for all measured water tolerance values. Quantitative 13C HPLC measurements reveal chemical structure information during the initial stage of the melamine-formaldehyde condensation. Raman spectroscopy is an outstanding technique for measuring e.g. the amount of free melamine in cured MF resins. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.843466 Item 50 Polymer Degradation and Stability 75, No.2, 2002, p.229-36 NOVEL OLIGOMERIC AMINES AS COSYNERGISTS FOR THE PHOTOSENSITISED CROSSLINKING OF A TRIACRYLATE RESIN Allen N S; Ryabov S V; Edge M; Kobylinskyy S N; Pokcholenko A A; Voitenko Z V Manchester,Metropolitan University; Ukraine,National Academy of Sciences; Kiev,Taras Shevchenko University Novel oligomeric amines have been synthesised that can be used as activators for the photoinitiated polymerisation of acrylates. A series of oligomeric amines with a range of molecular weights, endterminated tertiary amine groups and a different backbone were made on a base of Huntsman commercial products. These were characterised by IR, mass and NMR spectroscopy. The kinetics of polymerisation of a triacrylate monomer using the synthesised oligomers were measured by real time infra red spectroscopy and microwave photodielectrometry. Varying the chemical structure of the oligomers gave different polymer properties and rates of polymerisation. 20 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; UKRAINE; WESTERN EUROPE

Accession no.842721 Item 51 Journal of Applied Polymer Science 81, No.7, 15th Aug.2001, p.1670-4 DYNAMIC LIGHT-SCATTERING CHARACTERIZATION OF THE MOLECULAR WEIGHT DISTRIBUTION OF UNFRACTIONATED POLYIMIDE Siddiq M; Chi Wu Gomal,University; Hong Kong,Chinese University A dynamic laser light scattering method was used to characterise an unfractionated polyimide in chloroform at 25C. The relatively small angular and concentration dependencies and translational diffusion coefficients measured by this technique enabled the polyimide to be characterised from only one measurement at a finite

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References and Abstracts

concentration and small scattering angle. Thus, this method could be used to characterise the molecular weight distribution of polyimide from the measured line width distribution. 18 refs. CHINA; PAKISTAN

Accession no.842703 Item 52 Revista de Plasticos Modernos 81, No.538, April 2001, p.461-6 Spanish APPLICATION OF INFRARED SPECTROSCOPY AND THERMAL ANALYSIS IN MONITORING THE CURE OF THERMOSETTING RESINS USED IN THE AIRCRAFT INDUSTRY Sanchez-Blazquez A CASA The amine cure of Hexcel 8552 epoxy resin, for use as the matrix in carbon fibre-reinforced composites for application in aircraft construction, was monitored by near-infrared spectroscopy. This technique was validated by comparison of the results with those obtained by modulated DSC. 18 refs. HEXCEL COMPOSITES EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.842573 Item 53 Applied Spectroscopy 55, No.11, Nov. 2001, p.1514-22 RAMAN SPECTROSCOPY DETERMINATION OF THE THERMOPLASTIC CONTENT WITHIN EPOXY RESIN-COPOLYETHERSULFONE BLENDS van Overbeke E; Devaux J; Legras R; Carter J T; McGrail P T; Carlier V Louvain,Universite Catholique; ICI Details are given of the possibility of using Raman spectroscopy to determine the local thermoplastic content within an epoxy resin/copolyethersulphone blend. The required calibration of the Raman data is presented. The applicability of the calibrations to blends containing chlorine-ended copolyethersulphone is discussed. Results obtained with small or large Raman confocal holes were also compared. 40 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.838755 Item 54 Shawbury, Rapra Technology Ltd., 2001, pp.148. 30 cms. Rapra Review Rept. Vol.12, No.7, 2001; NALOAN RUBBER ANALYSIS - POLYMERS, COMPOUNDS AND PRODUCTS

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Forrest M J Rapra Technology Ltd. Edited by: Ward S (Rapra Technology Ltd.) Rapra.Review Rept. No.139 A number of elemental, spectroscopic, chromatographic and thermal techniques are described for the analysis of rubber compounds and products. This review aims to provide an introduction to the techniques and methods that are used to carry out quality control work on rubbers, to investigate the failure of rubber products and to deformulate rubber compounds. 379 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.838077 Item 55 Nottingham, Nottingham University Press, 2000, pp.55, 21cm, 99211 REFRACTIVE INCREMENT DATA-BOOK FOR POLYMER AND BIOMOLECULAR SCIENTISTS Theisen, J C; Deacon M P; Harding S E Nottingham,University This book provides a comprehensive survey of published experimental values for the refractive index increment (dn/dc) for specific macromolecules in specific solvents and conditions. Fully referenced. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.837002 Item 56 Macromolecules 34, No.20, 25th Sept.2001, p.7197-209 CHANGES IN MOLECULAR DYNAMICS DURING THE BULK POLYMERIZATION OF AN EPOXIDE/DIAMINE MIXTURE CONTAINING INERT DILUENTS AS STUDIED USING DIELECTRIC RELAXATION SPECTROSCOPY Williams G; Smith I K; Aldridge G A; Holmes P A; Varma S Wales,University; Pilkington Technology Centre Real time dielectric relaxation spectroscopy was used to study changes in the dipole relaxations and ionic conductivity during polymerisation of reactive epoxide/ diamine (bisphenol A diglycidyl ether (DGEBA)/4,4'diaminodicyclohexylmethane (PACM)) systems at 60C containing either decalin (DEC) or di-n-butyl phthalate (DBP) as diluents. For diluent concentrations up to 20% (w/w), the main effect of the diluent was to displace the dielectric alpha-relaxation process to higher frequencies, thereby increasing the time required for glass formation compared with that of the unplasticised system. For higher diluent concentrations, the permittivity behaviour for DGEBA/PACM/DBP systems showed that an elastomer rather than a glass was formed. The same results were

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presented as impedance which emphasised changes in the ac ionic conductivity with time. Qualitative differences were observed for the behaviour of impedance at low and high diluent concentrations. For these systems, changes in molecular mobility with time could be judged by the permittivity behaviour but not by the impedance behaviour. The results were discussed. 39 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.836473 Item 57 Journal of Applied Polymer Science 82, No.7, 14th Nov.2001, p.1593-9 MONITORING WATER UPTAKE OF POLYURETHANES BY IN SITU FLUORESCENCE TECHNIQUE Hakala K; Vatanparast R; Vuorimaa E; Lemmetyinen H Tampere,University of Technology Water absorption of three different polyurethane adhesives, at two different temperatures, was determined by gravimetric methods, and by a fluorescence method involving the use of extrinsic fluorescent probes. It was shown that agreement between the two methods was high, providing that an intensity ratio method was used where the ratio between the highest and lowest intensity changes in the fluorescent emission bands was determined in the spectroscopic method. By using the ratio technique, interferences from small changes in temperature, relative humidity, sample thickness, distribution, and diffusion of the probe could be ignored. 16 refs. EUROPEAN UNION; FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.834842 Item 58 Shawbury, Rapra Technology Ltd., 2001, pp.158. 29 cms. 17/8/01. Rapra Review Rept. 125. Vol. 11, No.5, 2001. NALOAN STRUCTURAL STUDIES OF POLYMERS BY SOLUTION NMR Cheng H N Hercules Inc. Edited by: Ward S (Rapra Technology Ltd.) Rapra.Review Rept.No.125 Nuclear magnetic resonance spectroscopy is discussed in terms of its use as an analytical technique for the study of polymer microstructure. In view of the size of the literature, this review concentrates on the studies of microstructure for polymers in solution, and is divided according to the different polymer types: addition polymers, condensation polymers, other polymeric materials, and polymer reactions. Selected recent developments are described, and include additive shift rules and the rotational isomeric state model; 2D NMR,

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isotopic labelling, analytical and simulation approaches, and hyphenated techniques. 515 refs. Photocopies and loans of this document are not available from Rapra. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA; WESTERN EUROPE

Accession no.834295 Item 59 Polymer Bulletin 47, No.1, Sept.2001, p.55-63 STUDY OF CURING KINETICS OF LADDERLIKE POLYEPOXYSILOXANE Pramoda K P; Yuhui Lin; Wei-yu Chen; Chung T S Singapore,Institute of Materials Research & Engineering; Singapore,National University Three polyepoxysiloxanes were prepared: (1) AC - with alkyl groups and epoxy groups grafted to the ladder-like polysilsesquioxane chain; (2) ACP - with alkyl groups, phenyl groups and epoxy groups grafted to the ladderlike chain; and (3) AP - with phenyl groups and epoxy groups in the ladder-like chain. The curing kinetics of these three polyepoxysiloxanes were studied. The curing was studied with and without the curing agent 1,3-bis(3aminopropyl)tetramethyldisiloxane. Without curing agent the curing behaviour depends on the curing conditions and the physical properties of the resulting material. The curing kinetics are influenced by such factors as the polymer structure, molecular weight and properties of the curing agent. The effects of the curing agent were examined using the AP epoxy treated with 2 weight percent of 1,3-bis(3-aminopropyl)tetramethyldisiloxane using DSC and FTIR. It was found that the curing reaction occurred via the epoxy functionality. The apparent activation energies were determined to be of the order: AC greater than ACP which was greater than AP, as the long alkyl chains tend to prevent the hydroxy groups from reaching the epoxy rings. No big change was observed in the activation energy between AP epoxy with or without curing agent. These polyepoxysiloxanes may be useful for electronic applications. 16 refs. SINGAPORE

Accession no.833644 Item 60 Polymer Degradation and Stability 73, No.3, 2001, p.485-90 SPECTROMECHANICAL ANALYSIS OF THE STRUCTURE AND OXIDATION OF PMR THERMOSET THERMALLY-STABLE RESINS Regnier N; Berriot J; Lafontaine E; Mortaigne B DGA/Centre Technique d’Arcueil Solid phase nuclear magnetic resonance spectroscopy and mechanical analysis, using both tensile testing and a torsion pendulum, were used to study the effects of long term oxidation on the mechanical properties of a high temperature thermosetting polyimide. Molecular

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References and Abstracts

models of the polyimide were also used in the study to help understand the mechanism of oxidation. It appears that mechanical properties are predominantly modified by oxidation of the surface, giving a rigid surface layer. The structure of this surface has yet to be determined. 11 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.831833 Item 61 Polymer Testing 20, No.7, 2001, p.795-803 A NEW METHOD FOR PREDICTING THE THERMAL OXIDATION OF THERMOSET MATRICES. APPLICATION TO AN AMINE CROSSLINKED EPOXY Colin X; Marais C; Verdu J ONERA; ENSAM A method, based on a differential equation which couples oxygen diffusion rate and its chemical consumption rate, to predict the oxidised thickness of an aromatic amine crosslinked epoxy resin under oxidation slightly below its glass transition temperature is demonstrated. Permeation tests to determine oxygen diffusivity and solubility in the polymer and tests to determine the kinetic parameters of oxygen degradation at different partial pressures are required to give information on the equation parameters, but model predictions agree well with experimental results determined from optical microscopy, gravimetry and infrared spectroscopy at all temperatures considered in the initial period of exposure. Practical problems with the model are discussed. 27 refs EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.830220 Item 62 Journal of Applied Polymer Science 81, No.8, 22nd August 2001, p.1902-13 DYNAMIC MECHANICAL ANALYSIS STUDY OF THE CURING OF PHENOLFORMALDEHYDE NOVOLAC RESINS Markovic S; Dunjic B; Zlatanic A; Djonlagic J Belgrade,University Using dynamic mechanical analysis the curing reactions of typical phenol-formaldehyde novolac resins were followed. The evolution of various rheological parameters was recorded for samples of the resins on cloth. A thirdorder phenomenological equation described the curing reaction. The influences of the structure, composition and physical treatment on the curing kinetics were evaluated. 20 refs. EASTERN EUROPE; YUGOSLAVIA

Accession no.829458

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Item 63 Journal of Applied Polymer Science 81, No.10, 6th Sept.2001, p.2347-51 CURING OF EPOXIDES WITH O,O-DI-T-BUTYL PHENYLPHOSPHONATE AS THERMALLY LATENT INITIATOR Kim M; Sanda F; Endo T Tokyo,Institute of Technology; Yamagata,University The polymerisation of glycidyl phenyl ether using ditert-butyl phenyl phosphonate (BP) as a thermally latent initiator was studied as a model reaction for the curing of an epoxy resin. Various Lewis acids, ammonium salts and methyl cyanoacetate were examined as activators but zinc chloride proved the most effective. The reactions were studied using NMR spectroscopy and molecular weight determined by gel permeation chromatography. Thermal properties were examined using calorimetry and thermogravimetric analysis. The curing of a commercial epoxy resin using the optimised system at 150 degrees centigrade was also reported, as was the fact that no initiation of cure took place at room temperature over a period of 7 months. 14 refs. JAPAN

Accession no.829333 Item 64 Journal of Polymer Science: Polymer Chemistry Edition 39, No.15, 1st August 2001, p.2658-69 VARIOUS SILICON-CONTAINING POLYMERS WITH SI(H)-TRIPLE BONDED C-C UNITS Itoh M; Iwata K; Ishikawa J-I; Sukawa H; Kimura H; Okita K Fukushima,National College of Technology; Mitsui Chemicals Inc.; Akita,National College of Technology; Japan,Chemical Innovation Institute Dehydrogenative polycondensation between one of four hydrosilanes and one of four diethynyl compounds was used to produce a range of nine different thermosetting polymers containing two triple bonded carbon atoms linked to a silicon atom with a single hydrogen attached. Characteristics of each polymer were examined using spectroscopy, chromatography and thermogravimetric analysis. All polymers were easily mouldable and had good solubility. When crosslinked, which was said to take place between a triple bonded carbon atom and the silicon with the hydrogen linking onto the second triple bonded carbon, high thermal stability was generally shown with less than 10 percent weight loss at 1000 degrees centigrade. Thermal stability was examined with reference to polymer structure, and when two hydrosilanes or two diethynyl compounds were used, thermally crosslinkable copolymers were produced. 15 refs. JAPAN

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Item 65 Polymer 42, No.19, 2001, p.8297-301 CONFORMATION OF CRYSTALLINE POLY(PHENYLENE SULPHIDE) Hay J N; Luck D A Birmingham,University Wide-angle x-ray diffraction patterns of a wide range of materials with different degrees of crystallinity were used to calculate the crystallographic structure of crystalline poly(phenylene sulphide). The dimensions of the orthorhombic unit cell were refined by a least squares method. The torsional angle of the C-S-C bond was determined to be 108 degrees and the phenylene groups to be arranged at 45 degrees to the plane of the molecular chain using computer modelling and potential energy minimisation. These results were confirmed by comparison of computed and measured x-ray diffraction intensities. 11 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.826673 Item 66 Polymer 42, No.19, 2001, p.7943-52 QUANTITATIVE MAGNETIC RESONANCE IMAGING STUDY OF WATER UPTAKE BY POLYAMIDE 4,6 Adriaensens P; Pollaris A; Carleer R; Vanderzande D; Gelan J; Litvinov V M; Tijssen J Limburg,University; DSM Research The water absorption by polyamide 4,6 (PA46) plates was studied by NMR relaxation experiments and magnetic resonance imaging (MRI). PA46 was found to absorb more water compared to polyamides 6 and 6,6 despite the higher crystallinity. Relaxation measurements demonstrate that the volume averaged molecular mobility of the absorbed water molecules in PA46 is higher than in PA6 and PA66. Fast exchange between free water and water molecules bound via hydrogen bonds to amide groups is suggested by the quantitative relaxation results of water saturated PA46. MRI showed a gradual decrease in the amount and the molecular mobility relaxation behaviour of water from the surface towards the core part of PA46 plates. This can be explained by a very large crystallisation rate of PA46, preventing the close coupling of amide groups in the amorphous phase and results in a larger mean distance between the amide groups, especially in the outer part of the PA46 plates. There is an increase in the density of the amorphous phase during annealing, which results in a lower water uptake and a lower mobility of the absorbed water molecules. 38 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

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Item 67 Polymer Journal (Japan) 33, No.3, 2001, p.263-9 PREPARATION OF A NOVEL INFRARED PHOTOINITIATOR AND KINETIC MONITORING OF PHOTOPOLYMERIZATION BY REAL TIME FT-IR SPECTROSCOPY Li B; Zhang S; Tang L; Zhou Q Tsinghua,University A novel cationic cyanine dye-borate complex, 1 , 3 , 3 , 1 ' , 3 ' , 3 ' - h e x a m e t h y l - 11 - c h l o r o - 1 0 , 1 2 propylenetricarbocyanine triphenylbutylborate was prepared and used as the photoinitiator in infrared laserinduced photopolymerisation of acrylates. It had a maximum electron absorption at 768 nm, this matched well with the output wavelength of the adopted infrared laser diode. The polymerisation process of phthalicdiglycol diacrylate, binder, photoinitiator and solvent was monitored through real time FT-IR spectroscopy. The double bond conversion was determined from the reduction of the absorption of acrylate monomer at 1635 cm-1 and 1620 cm-1. The polymerisation rate increased rapidly as the concentration of the photoinitiator rose but decreased when the concentration reached a critical value. The ultimate double bond conversion of sample increased when the infrared laser power was enhanced, and they fell greatly as the thickness of the polymeric sample layer increased. 30 refs. CHINA

Accession no.826624 Item 68 Cheltenham, Stanley Thornes, 2000, pp.viii, 481, 23cm, 91T POLYMER CHARACTERISATION - PHYSICAL TECHNIQUES - SECOND EDITION Campbell D; Pethrick R A; White J R Northumbria,University; Strathclyde,University; Newcastle Upon Tyne,University This guide provides a detailed survey of the characterisation techniques used to analyse the properties of polymers and polymer-based materials. The book is written for advanced undergraduates but also suitable for industrial scientists and technologists. Main headings include: the purpose of characterisation; Molecular architecture; Amorphous polymers; Crystallising polymers; Molecular mass determination; Introduction to spectroscopic techniques; Ultravioletvisible spectroscopy; Vibrational spectroscopy - infrared and raman spectroscopy; Nuclear magnetic resonance spectroscopy; Electron spin resonance spectroscopy; Xray diffraction; Transmission electron microscopy and diffraction; Scanning electron microscopy; Light optical techniques; Thermal analysis; Density, surface properties and neutron diffraction; multiple characterisation applications; Theoretical predictions of the physical

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References and Abstracts

properties of polymeric materials. Each chapter is well referenced. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.826526 Item 69 Journal of Polymer Engineering Vol.21 No.4, July-Aug.2001, p.389-99 FORMALDEHYDE RESINS FROM PNONYLPHENOL AND RESIN ACIDS Mustata F; Bicu I Petru Poni,Institute of Macromolecular Chemistry Phenol formaldehyde resins were prepared from varying proportions of para-nonylphenol, formaldehyde and “resin acids” extracted from rosin. The molecular weight and viscosity were determined and the resins characterised by IR, and NMR spectroscopy and thermogravimetric analysis. The molecular weights of the resins were low, in the range 700-1200. These materials were then mixed with ethylhexyl acrylate-acrylic acid copolymer to give a pressure sensitive adhesive composition which was used to make adhesive tape. These compositions showed better adhesive properties than the acrylic copolymer alone. 19 refs. EASTERN EUROPE; RUMANIA

Accession no.826309 Item 70 Shawbury, Rapra Technology Ltd., 2001, pp.144. 30 cms., 5/9/01. Rapra Review Rept. 134, Vol. 12, No. 2, 1997. NALOAN INFRARED AND RAMAN SPECTROSCOPY OF POLYMERS Koenig J L Case Western Reserve University Edited by: Ward S (Rapra Technology Ltd.) Rapra.Review Rept. No. 134 Vibrational spectroscopy represents two physically different, yet complementary spectroscopic techniques: infrared and Raman spectroscopy. Vibrational spectroscopy is used as an analytical tool for polymer characterisation, providing information relating to composition, structure, conformation, and intermolecular interactions using simple sampling techniques. The advantages of their use and their capabilities as analytical tools are examined. The elementary theory of vibrational spectroscopy is explained, together with selection criteria for IR and Raman spectroscopy techniques. This is followed by chapters on vibrational spectroscopic instrumentation; sampling for vibrational spectroscopy; measuring polymer orientation with IR and Raman spectroscopy; and examples of IR and Raman applications to polymer characterisation. 413 refs. Photocopies and loans of this document are not available from Rapra. USA

Accession no.825822

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Item 71 Journal of Polymer Science: Polymer Physics Edition 39, No.12, 15th June 2001, p.1326-36 NETWORK FORMATION STUDIED BY TEMPERATURE SCANNING BRILLOUIN SCATTERING AND DIFFERENTIAL SCANNING CALORIMETRY TECHNIQUES. PART II Castiglia S R V; Fioretto D; Verdini L; Samios D Rio Grande Do Sul,Universidade Federal; Perugia,University The curing reaction of the epoxy system 1,4-butanediol diglycidyl ether (EP) with cis-1,2-cyclohexanedicarboxylic anhydride (CH) and triethylamine (TEA) as initiator was studied with temperature scanning Brillouin Spectroscopy (TSBS) and differential scanning calorimetry (DSC). The progression of the curing reaction (liquid-gel-solid) and resulting network formation was investigated as a function of the epoxy molar fraction (Xep), for sample compositions varying from an epoxy excess to an anhydride excess. The final conversion factors alpha rDSC and alpha rTSBS and the kinetic parameters EDSC and ETSBS were found to be dependent on Xep. The experimental gelation point (Pgel) behaviour and the expected theoretical one, described by Flory theory were compared. 28 refs. BRAZIL; EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.825480 Item 72 Analytical Chemistry 73, No.13, 1st July 2001, p.360A-9A FTIR IMAGES Koenig J L; Shi-Qing Wang; Bhargava R Case Western Reserve University; Akron,University; US,National Institutes of Health A brief introduction to FTIR microspectroscopy is presented and the required instrumentation and capabilities, such as performing new applications for polymeric materials analysis, are discussed. Noise and other artefacts are described with reference to data processing and quantification, collecting and processing S/N data, data extraction, and data visualisation. Applications of imaging considered include materials analysis and characterisation, polymer laminates, semicrystalline polymers and their blends, polymer-liquid systems, polymer-liquid crystal systems and determination of phase diagrams. 27 refs. USA

Accession no.825224 Item 73 Shawbury, Rapra Technology Ltd., 2001, p.iv, 174, 25cm, 91T EASY IDENTIFICATION OF PLASTICS AND RUBBERS

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References and Abstracts

VERLAYE G A L; ROEGES N P G; DE MOOR MO KaHo Sint-Lieven This book presents an identification scheme developed over the last thirty years for thermoplastics, common thermosets, a few copolymers and elastomers. The techniques used are based on simple tests such as the behaviour of polymers in liquids and in a flame. The book also covers Infrared spectroscopy. Main headings are: Simple tests (melting, solubility, burning characteristics, odour recognition, dripping, flotation, halogen test, nitrogen- and sulphur-test); Recording an IR spectrum; Identification flow charts; Thermoplastics; Cellulose and starch; Thermosets; Elastomers. (15 Refs) BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

softwood and two semi-hard woods, respectively. The particles were used untreated and chemically modified with maleic anhydride. For the characterisation of untreated and treated flours, thermogravimetric analysis and analytical techniques were utilised. Dispersion of the fibrous particles, in addition to maximum fibre concentration (accompanied by complete wetting of the wood fibres) was dependent on the treatment and on the wood species utilised. Bending and compression tests suggested some improvement in the performance of the composites, if the wood flour was previously esterified. Changes in the fracture surfaces due to maleic anhydride treatment of the fibres were observed using scanning electron microscopy. 12 refs. ARGENTINA

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Item 74 UTECH 2000. Proceedings of a conference held The Hague, Netherlands, 28th-30th March 2000. London, 2000, Other Rigid Foam Developments Session, Paper 1, pp.4, 012 LONG-TERM ENERGY EFFICIENCY OF PUINSULATION FOR REFRIGERATION Seifert H; Biedermann A Elastogran GmbH (Crain Communications Ltd.; European Isocyanate Producers’ Association)

Item 76 UTECH 2000. Proceedings of a conference held The Hague, Netherlands, 28th-30th March 2000. London, 2000, Innovations: Flexible Foam Developments Session, Paper 5, pp.4, 012 VOC DETECTION IN POLYURETHANE FLEXIBLE FOAMS Occhiello E; Tavan M; Pannocchia P; Fava F EniChem (Crain Communications Ltd.; European Isocyanate Producers’ Association)

The ageing behaviour of rigid PU foams was investigated using gas chromatographic quantitative evaluation of the cell gas composition in the foams. The change in thermal conductivity of the foams during ageing was also examined as was the dimensional stability of the foams under diffusion open conditions and the results obtained correlated with the K x A-values from refrigerator cabinets via the change in cell gas composition. The data obtained revealed that the ageing process of appliances could be simulated in a tenth of the time by measuring diffusion opened PU foams. 2 refs.

The detection of volatile organic compounds in polyols and PU foams using SPME, gas chromatography and gas chromatography-mass spectroscopy is demonstrated.

EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; NETHERLANDS; WESTERN EUROPE

Accession no.824859 Item 75 Molecular Crystals & Liquid Crystals Vol.353, 2000, p.95-108 COMPOSITES MADE FROM LIGNOCELLULOSICS AND THERMOSET POLYMERS Aramguren M I; Marcovich N E; Reboredo M M INTEMA Preparation and testing of composites from a styrene/ unsaturated polyester thermoset matrix and wood flours from different wood species was carried out. Studies were carried out on Pine (Pino Eliottis), eucaliptus (Eucaliptus Saligna) and marmelero (Ruprechia Laviflora), a

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EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; NETHERLANDS; WESTERN EUROPE

Accession no.823982 Item 77 Journal of Applied Polymer Science 81, No.4, 25th July 2001, p.889-900 CURING OF EPOXY-URETHANE COPOLYMERS IN A HEATED MOLD: EFFECT OF THE CURING CONDITIONS ON THE PHASE-SEPARATION PROCESS Stefani P M; Moschiar S M; Aranguren M I; Marieta C; Mondragon I Mar del Plata,University; Pais Vasco,Universidad In studying the curing of an epoxy-urethane copolymer in a heated mould, Araldyt epoxy resin was co-reacted with a urethane prepolymer (PU) (Desmocar) through a mixture (Distraltec) of cycloaliphatic amines, acting as a crosslinking agent, in order to find the effect of curing conditions and PU concentration on the time/temperature profiles as measured in the mould and the resultant morphologies produced. With increase in PU concentration the maximum mould temperature decreased because of the dilution effect of the elastomer on the heat of reaction, and the Tg of the sample also decreased. Phase

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References and Abstracts

separation, which depends on the degree of conversion and the temperature attained in the mould was analysed using the experimental data and a mathematical model which predicted the temperature and degree of conversion throughout the mould. The characteristics of the dispersed phase for different formulations and curing conditions were determined by means of scanning electron microscopy and atomic force microscopy. The results showed that the size of the dispersed phase was directly related to the PU concentration, whereas the curing area and curing temperature had little effect on the separated phase over the range studied, i.e. 70-100 deg.C. Superposition of the phase diagrams on the conversion/ temperature trajectories obtained during curing provided an explanation of the morphologies obtained. 34 refs.

laser-induced (UV) decomposition. The polyimide system decomposes thermally in distinct steps, i.e., first the imide ring, without elimination of the carbonyl groups, followed by the aromatic system and then the carbonyl groups. Several intermediates, such as nitriles and alkynes, are identified. The quantitative analysis of the spectra suggests that Kapton. decomposes in two steps, i.e., as a growing particle with shrinking core followed by a shrinking particle. The growing particle with shrinking core is the non-reacted polymer as core and a polyamic structure as the growing part, while the shrinking particle is the complete pyrolysis of the polymer. The activation energies for these two steps were determined. The reaction rate appears to be diffusion controlled at low temperatures and surface reaction controlled at higher temperatures.

ARGENTINA; EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

SWITZERLAND; WESTERN EUROPE

Accession no.823814 Item 78 DEVELOPMENTS IN POLYMER ANALYSIS AND CHARACTERISATION Proceedings of a conference held Shawbury, UK, 10th May 1999. Shawbury, 1999, Paper 4, p.1-15, 012 CHEMICAL CHARACTERISATION OF POLYURETHANES Forrest M J Rapra Technology Ltd. (Rapra Technology Ltd.) Polyurethane chemistry is briefly outlined, additives generally used in polyurethanes are indicated and the analytical techniques used to characterise the structure, composition and properties of PUs and PU-based products are discussed in a comprehensive manner. Techniques covered include spectroscopic, chromatographic techniques and miscellaneous techniques, such as wet chemistry techniques. Sections are included dealing with the characterisation of polymer structure and starting materials, molecular weight determinations, characterisation of additives and cure reaction studies. 14 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.822952 Item 79 Applied Spectroscopy 55, No.4, April 2001, p.412-9 PYROLYSIS OF KAPTON IN AIR; AN IN SITU DRIFT STUDY Ortelli E E; Geiger F; Lippert T; Wokaun A Paul-Scherrer-Institut; ETH-Zentrum Diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy is used to study the pyrolysis of polyimide (Kapton). The samples are prepared in a KBr matrix, which does not show pronounced interferences, such as increased emissivity, during the measurements. The pyrolysis of Kapton reveals pronounced differences from

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Accession no.822816 Item 80 Polymer Degradation and Stability 72, No.1, 2001, p.125-31 THERMAL DEGRADATION OF THERMOPLASTIC AND THERMOSETTING POLYMERS INDUCED BY LASER RADIATION AND IT’S STUDY BY FTIR SPECTROSCOPY Bormashenko E; Pogreb R; Shesnev A; Shulzinger E; Bormashenko Y; Sutovski S; Pogreb Z; Katzir A Israel,College of Judea and Samaria; Tel Aviv,University; Polytris Ltd. Thin films of an epoxy resin, polyethylene and polysulphone were exposed to powerful laser radiation. Absorbance spectra were measured using FTIR spectrometry. Decay of the characteristics of the polymers was found to occur under radiation. The observed effect has been presented mathematically. The new method is proposed for the study of the degradation process of polymers. 9 refs. ISRAEL

Accession no.820845 Item 81 Polymer Degradation and Stability 72, No.1, 2001, p.115-24 EVALUATION OF ACCELERATED WEATHERING TESTS FOR THREE PAINT SYSTEMS: A COMPARATIVE STUDY OF THEIR AGEING BEHAVIOUR Perrin F X; Irgoyen M; Aragon E; Vernet J L Toulon,University The chemical evolution of epoxy-acrylurethane, alkyd and chlorinated rubber paints under the influence of five standard tests was followed using IR spectroscopy. The physical property variation was also examined. A wide difference in the behaviour of the three paint systems to the effects of the tests was found. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

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Item 82 London, Chapman & Hall, 1994, ppxii, 368, 24cm CHARACTERISATION OF SOLID POLYMERSNEW TECHNIQUES AND DEVELOPMENTS Sheffield,Hallam University Edited by: Spells S J This book provides a review of techniques and developments in the field of characterisation of solid polymers. It particularly addresses the techniques relating to scanning tunnelling and atomic force microscopy but also discusses experimental advances in well-established techniques such as infrared spectroscopy. Main headings include Electron crystallography of linear polymers, New techniques in microscopy, X-ray studies using synchrotron radiation, Neutron-scattering techniques, Mixed-crystal infra-red spectroscopy, Raman spectroscopy and mechanical properties, NMR spectroscopy of solid polymer systems, Polymer characterisation by XPS and SIMS. Each chapter is well referenced. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.817928 Item 83 Advances in Polymer Science Vol.154, 2001, p.87-141 DYNAMICS IN THE GLASSY STATE AND NEAR THE GLASS TRANSITION OF AMORPHOUS POLYMERS AS STUDIED BY NEUTRON SCATTERING Kanaya T; Kaji K Kyoto,University Recent progress of studies on dynamics in the glassy states and near the glass transition of amorphous polymers as revealed by inelastic and quasielastic neutron scattering is described. Emphasis is placed on low energy excitation (boson peak) in the glassy states; fast process in picosecond order; E-process related to conformational transitions; and dynamical heterogeneity as revealed by non-Gaussian parameter. 152 refs. JAPAN

Accession no.816041 Item 84 Journal of Polymer Science: Polymer Physics Edition 39, No.3, 1st Feb.2001, p.326-31 NEAR-INFRARED SPECTROSCOPIC STUDIES ON THE CURE BEHAVIORS OF THE CAE/ DGEBA BLEND SYSTEM INITIATED BY A THERMAL LATENT CATALYST Park S-J; Kwak G-H; Seo M-K; Lee J-R Korea,Research Institute of Chemical Technology Using near-infra-red spectroscopy the use of Nbenzylpyrazinium hexafluoroantimonate as a thermal latent initiator for the blend systems consisting of cycloaliphatic epoxy and diglycidyl ether of bisphenol

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epoxy was investigated. The study showed that more than one type of reaction took place and that the Nbenzylpyrazinium hexafluoroantimonate was an excellent thermal initiator without any co-inititator. Characteristic N-IR band assignments were used to evaluate the reactive kinetics and were shown to be an appropriate method for studying cure behaviour. 17 refs. KOREA

Accession no.814124 Item 85 Polymer 42, No.12, 2001, p.5189-98 CURE KINETICS AND ULTIMATE PROPERTIES OF A TETRAFUNCTIONAL EPOXY RESIN TOUGHENED BY A PERFLUORO-ETHER OLIGOMER Musto P; Martuscelli E; Ragosta G; Mascia L Italy,National Research Council; Loughborough,University The cure characteristics of a typical commercial composition of a tetrafunctional epoxy resin (tetraglycidyl-4,4'-diaminodiphenyl-methane) to which a perfluoro-ether oligomer impact modifier was added were investigated using Fourier Transform Near Infrared spectroscopy. Modification to the cure rate, but not to the final conversion of the reactants, relative to the unmodified resin was observed, and this was considered with respect to the curing mechanism. Phase structure of the cured resins produced with different additions of the oligomer was examined by both scanning electron microscopy and dynamic mechanical thermal analysis, but no evidence of any two phase morphology was observed. When the amount of modifier added to the reacting mixture exceeded 10 parts by weight, the fracture parameter was found to increase significantly. 39 refs EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; UK; WESTERN EUROPE

Accession no.814038 Item 86 Shawbury, 1999, 9 papers DEVELOPMENTS IN POLYMER ANALYSIS AND CHARACTERISATION. PROCEEDINGS OF A CONFERENCE HELD SHAWBURY, UK, 10TH MAY 1999 (Rapra Technology Ltd.) Nine mainly referenced papers are presented describing various aspects of polymer analysis and characterisation. Techniques described include infrared imaging, microthermal analysis, surface photoelectron spectroscopy and mass spectroscopy, gas chromatography, and high temperature gel permeation chromatography. Other subjects described include interlaboratory tests on the repeatability and reproducibility of thermal analysis and the chemical analysis and characterisation of polyurethanes.

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EUROPEAN COMMUNITY; EUROPEAN UNION; SWITZERLAND; UK; WESTERN EUROPE

Accession no.813920 Item 87 Cambridge, Woodhead Publishing Ltd., 1998, pp.xiv,319. 24cm. 627 MICROSTRUCTURAL CHARACTERISATION OF FIBRE-REINFORCED COMPOSITES Edited by: Summerscales J (Plymouth,University) This book contains nine thoroughly-referenced chapters upon the structural study and characterisation of fibrereinforced plastics, woven fabrics, and yarns. Techniques discussed in depth include optical and electron microscopy, scanning laser microscopy, computer modelling of fibres and yarns, and Raman spectroscopy. Techniques for the estimation of volume fraction, determination of mechanical properties, and mathematical theory of structures are also discussed. Both technical procedures and interpretation of results are discussed in depth. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.806375 Item 88 Polymer 42, No.8, 2001, p.3533-57 CHANGES IN MOLECULAR DYNAMICS DURING THE BULK POLYMERISATION OF AN EPOXIDE/BOROXINE MIXTURE AS STUDIED BY DIELECTRIC RELAXATION SPECTROSCOPY, REVEALING DIRECT EVIDENCE FOR A FLOOR TEMPERATURE FOR REACTION Williams G; Smith I K; Aldridge G A; Holmes P; Varma S Swansea,University of Wales; Pilkington Technology Centre Changes occurring in the dielectric alpha-relaxation and ion conductivity during the bulk polymerisation of an epoxide/boroxine system at various polymerisation temperatures in the range 60 to 120C were investigated using real-time dielectric relaxation spectroscopy. The data obtained were analysed in terms of changes in molecular motion over time and the floor temperature below which a glass is formed and above which an elastomer is formed was determined. The TTT-diagram of Gillham et al. is modified to describe the evolution of Tg with time for different values of polymerisation temperatures. 48 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.806152 Item 89 Progress in Organic Coatings 40, Nos.1-4, Dec.2000, p.195-202

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THREE-DIMENSIONAL COMPOSITIONAL GRADIENTS IN WATER-BORNE URETHANES AND LATEXES: SPECTROSCOPIC APPROACHES Urban M W North Dakota State University Combined ATR and photoacoustic spectroscopies, together with IR and/or Raman surface imaging, were used to establish a three-dimensional representation of PU film formation and of the effect of copolymer/polymer blend latices on coalescence processes in styrene/n-butyl acrylate. The presence of macromolecular arrangements and interactions among various components near the filmair and the film-substrate interfaces could be effectively monitored using the ATR and step-scan photoacoustic FTIR spectroscopic techniques. Both approaches were capable of obtaining information from various surface depths and complemented each other if molecular level information from 0 to 150 micrometres into the film was sought. 60 refs. (25th Athens Conference on Organic Coatings, Vouliagmeni, Greece, July 1999) USA

Accession no.805135 Item 90 Polymer Plastics Technology and Engineering 39, No.5, 2000, p.937-43 STUDY OF THE CURING PROCESS OF AN EPOXY RESIN BY FTIR SPECTROSCOPY Canavate J; Colom X; Pages P; Carrasco F Catalunya,Universitat Politecnica; Girona,Universidad The curing process of an epoxy resin of glycidic polyether is studied using Fourier transform infrared spectroscopy. The influence of the hardener/resin ratio, temperature and curing time are determined. It is discussed which bands of the IR spectrum and what relation of their absorbances are most convenient to monitor the resin-curing process. 14 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.802541 Item 91 Polymer News 25, No.10, Oct.2000, p.359-60 ANALYSIS OF AIRCRAFT COATING BY SECONDARY ION MASS SPECTROSCOPY Usmani A M; Donley M UDC; Wright-Patterson Air Force Base An analysis was made of a flat aircraft coating using secondary ion mass spectroscopy, which revealed that the coating was a polyurethane C type based on isophorone diisocyanate, diethylene glycol and adipic acid. X-ray photoelectron spectroscopy was employed to determine pigments and extenders. 10 refs. USA

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References and Abstracts

Item 92 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 431 MID-INFRARED PROCESS CONTROL SYSTEMS FOR POLYMER MELTS AND FILM Bart J C J DSM Research (SPE) Online mid-infrared analysis is used for: the determination of additives in polymer melts; analysis of polymer and copolymer blends; polymerisation control by end group determination; determination of degrees of crosslinking; reaction monitoring, including curing, reaction kinetics, and end point determination; in-situ studies of molecular interactions; extrusion monitoring; and safety and environmental monitoring. 21 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.799946 Item 93 Antec 2000.Conference proceedings. Orlando, Fl., 7th-11th May, 2000, paper 430 NEAR-INFRARED SPECTROSCOPIC PRODUCT AND PROCESS CONTROL Bart J C J DSM Research (SPE) Near infrared spectroscopy is used for quality control, the identification and classification of polymeric materials, the monitoring of polymer melt composition and the monitoring of polymerisation processes. The modes used are: diffuse reflectance and transmission, transreflectance and reflectance. Industrial applications are discussed. 39 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.799945 Item 94 Macromolecules 33, No.22, 31st Oct.2000, p.8415-20 MASS SPECTROMETRY ANALYSIS OF HARD SEGMENT LENGTH DISTRIBUTION IN POLYURETHANES Yontz D J; Shaw Ling Hsu Massachusetts,University MALDI mass spectroscopy was used to determine the hard segment length distribution in poly(urea-urethane)s. Although hard segment length was expected to vary with water content in the initial formulations, the actual distribution was rather similar for all samples analysed. A more detailed analysis, however, revealed that the main difference was in the region corresponding to hard segments with greater than eight urea repeat units. This result had implications for both the origin of phase

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separation behaviour and the mechanical performance of phase-separated heterogeneous polymers. The similarity in hard segment distribution suggested that phase separation behaviour in these PU foams could be due solely to the orientational entropic contribution. The presence of these long hard segments, although not extensive, could contribute significantly to mechanical performance. MALDI also revealed the presence of side products. The amount of cyclic species, either isocyanurate or cyclic hard segments, varied from 2 to 4% for foams with different urea contents. 32 refs. USA

Accession no.798116 Item 95 Polymer Preprints. Volume 40. Number 2. August 1999. Conference proceedings. New Orleans, La., August 1999, p.669-70 USING FTIR TO DETERMINE THE EXTENT OF REACTION OF EPOXIES UNDER MICROWAVE ENERGY Stoffer J O; Zhang D; Crivello J V Missouri-Rolla,University; Rensselaer Polytechnic Institute (ACS,Div.of Polymer Chemistry) The bisaliphatic epoxy resin, 3,4-epoxycyclohexylmethyl, 3,4-epoxycyclohexylcarboxylate (a) is very reactive, commercially available, and of a low order of toxicity. The epoxide polymerises rapidly under either thermally or under microwave irradiation in the presence of initiators of diaryliodonium or triarylsulphonium salts (b). Although the detailed mechanism of polymerisation is not fully understood, it seems very probable that the epoxide (a) polymerise via a cationic mechanism after thermolysis of the initiators under conditions of both microwave irradiation and conventional thermal activation. The extent of reaction cannot be determined using solubility methods, because the molecule of the epoxide (a) has two epoxy groups, which make the polymer crosslinked and insoluble. A new method using DSC and FTIR has been developed. The observation that an FTIR peak of the epoxide (a) changes as polymerisation progresses is reported. An FTIR internal standard method is developed to monitor the extent of reaction. One advantage of the FTIR method is that it is not related to the mass of samples. 3 refs. USA

Accession no.797534 Item 96 West Conshohocken, PA, 2000, pp.6. NALOAN. ASTM D 4875-. TEST METHODS OF POLYURETHANE RAW MATERIALS: DETERMINATION OF THE POLYMERIZED ETHYLENE OXIDE CONTENT OF POLYETHER POLYOLS American Society for Testing & Materials

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References and Abstracts

ASTM D 4875Version 99. Photocopies and loans of this document are not available from Rapra. USA

Accession no.796565 Item 97 Polyurethanes Conference 2000. Conference proceedings. Boston, Ma., 8th-11th Oct.2000, p.377-382 DETERMINATION OF HYDROXYL NUMBER FOR POLYOLS BY A NEW DERIVATISATION MID-INFRARED SPECTROSCOPIC PROCEDURE Chaffin N; Samples S; Dix K; Frisch K Bayer Corp. (American Plastics Council,Alliance for the Polyurethanes Industry) Recent catalyst developments in the production of polyoxypropylene oxide (PPG) polyols have resulted in commercialisation of high molecular weight polyols not possible using conventional KOH base chemistry. While 8,000 and 12,000 molecular weight PPG diols, such as Acclaim 8200 and 12200 are a significant advance in the industry, these higher molecular weight polyols pose certain problems for the analyst. These high molecular weight polyols have lower concentrations of hydroxyl end group, making the standard methods of determining hydroxyl number difficult. A simple mid-IR spectroscopic procedure for determining polyol hydroxyl numbers from one to eight (mg KOH/g sample) is presented. The polyol is reacted with para-toluene sulphonyl isocyanate to form the urethane. The intensity of the urethane carbonyl band at 1746 cm-1 serves as the means of quantification. The procedure can be applied to virtually any polyol, including those with very high hydroxyl numbers, by simply increasing the dilution ratio. A modification of the method may be needed for polyols that have absorption that overlaps the urethane carbonyl band. A ‘cookbook’ procedure is provided for the analyst. 12 refs. USA

Accession no.794306 Item 98 West Conshohocken, Pa., 1997, pp.3. NALOAN ASTM D 1726-. TEST METHODS FOR HYDROLYZABLE CHLORIDE CONTENT OF LIQUID EPOXY RESINS American Society for Testing & Materials ASTM D 1726Version 90 (R1996). Photocopies and loans of this document are not available from Rapra. USA

Accession no.794006

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Item 99 Journal of Applied Polymer Science 78, No.11, 9th Dec.2000, p.1884-96 REACTIONS BETWEEN MELAMINE FORMALDEHYDE RESIN AND CELLULOSE: INFLUENCE OF PH Devallencourt C; Saiter J M; Capitaine D Rouen,University; OFITECH SA Carbon-13 NMR studies in the liquid state and DMA were performed on cellulose-melamine formaldehyde blends obtained from a sample of ashless filter paper immersed in aqueous solutions of a melamine-formaldehyde resin with a high NH ratio. The resin aqueous solution was studied at pH 6, 7 and 9. After curing at 85C, acid conditions were shown to improve the mechanical properties of the composite as a result of self-condensation reactions of the amino resin, while for the other pH values the mechanical properties of the cellulose were not changed because hydrolysis reactions mainly occurred. For cure performed at 140C and under acid conditions, the degree of crosslinking of the resin increased, while for the other pH values mainly cocondensation reactions occurred. Finally, from moisture sorption measurements performed on composite materials at pH 7 and for different relative humidity values, it was shown that the Langmuir absorption model was modified by the presence of the resin. 42 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.793638 Item 100 Polymer Composites 21, No.5, Oct.2000, p.745-50 RAMAN STUDY OF THE MICROSTRUCTURE CHANGES OF PHENOLIC RESIN DURING PYROLYSIS Ko T-H; Kuo W-S; Chang Y-H Feng Chia,University The effects of carbonisation and graphitisation at temperatures ranging from 300 to 2400C on changes in the microstructure of a phenol-formaldehyde resin were investigated using wide-angle X-ray diffraction and Raman spectroscopy. Variations in the crystal size of the cured resins as a function of carbonisation temperature and in the stacking height and crystal size of the carbonised resins as a function of pyrolysis temperature were examined and progressive structure ordering with increasing heat treatment temperature confirmed from the Raman spectra. 32 refs. TAIWAN

Accession no.790480 Item 101 Macromolecular Chemistry & Physics 201, No.12, 18th Aug.2000, p.1311-6

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References and Abstracts

COMPARISON OF DIFFERENT METHODS FOR THE DETERMINATION OF THE MOLAR MASS AND MOLAR MASS DISTRIBUTION OF POLY(ETHYLMETHYLSILOXANE) Goetz H; Maschke U; Wagner T; Rosenauer C; Martin K; Ritz S; Ewen B Max-Planck-Institut fuer Polymerforschung; Lille,Universite des Sciences et Technologies Calibration curves were established for poly(ethylmethylsiloxane) (PEMS) for both size exclusion chromatography and viscometry, because conventional PDMS standards produced results for molar masses of PEMS which were 15-40% higher than expected compared with measurements of the absolute molar mass values. Eleven low polydispersity linear PEMS samples with molar masses of 4-110 kg/mol were prepared by ringopening polymerisation of a cyclic monomer. Their molar masses were determined by MALDI-TOF mass spectrometry, light scattering, membrane osmometry, vapour pressure osmometry and viscometry. The results from the different methods were compared and discussed. Small angle neutron scattering experiments on a 50/50% protonated/deuterated PEMS blend exactly matched the molar mass obtained from the PEMS calibration curve for size exclusion chromatography. 18 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; GERMANY; WESTERN EUROPE

German QUANTITATIVE DETERMINATION OF SILICONES IN MASONRY PAINTS Lehnert R; Brendler E Huels StructurA GmbH; Freiburg,Institut fuer Analytische Chemie The use of silicon-29 magic angle spinning NMR spectroscopy for qualitative and quantitative analysis of the silicone resins used as binders in masonry paints is described. The possibility of differentiating between silicone resin binders and silicon resin additives using this technique is discussed. It is shown that true masonry paints, which are hydrophobic but still permeable to water vapour, can be differentiated from those which just contain a silicone oil water repellent. 7 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.785721 Item 104 Analytical Chemistry 72, No.12, 15th June 2000, p.129R-35R SUPERCRITICAL FLUID AND UNIFIED CHROMATOGRAPHY Chester T L; Pinkston J D Procter & Gamble Co.

Accession no.789753

A review is presented in the area of supercritical fluid and unified chromatography. 114 refs.

Item 102 Journal of Applied Polymer Science 78, No.4, 24th Oct.2000, p.808-15 EFFECTS OF PROMOTER AND CURING PROCESS ON EXFOLIATION BEHAVIOUR OF EPOXY/CLAY NANOCOMPOSITES Ke Y; Lu J; Yi X; Zhao J; Qi Z Chinese Academy of Sciences; Zhejiang,University; Beijing,Institute of Aeronautical Materials

USA

XRD, DSC and TEM have been used to study the effects of a curing process and a catalyst and coupling agent on the exfoliation behaviour of CH3(CH2)15NH3+-montmorillonite clay in an anhydride-cured epoxy clay system. The results showed that the organoclay is intercalated by the epoxy precursor during mixing, and the clay galleries continue to expand during curing but the Na+-montmorillonite clay is not intercalated during mixing or curing. The use of a promoter or coupling agent lowers the reaction temperature, and during curing the layered organoclay can be broken down into nanoscale structures, complete exfoliation is achieved at or before gelation. 20 refs.

Accession no.783748 Item 105 Analytical Chemistry 72, No.12, 15th June 2000, p.99R-110R SURFACE ANALYSIS: X-RAY PHOTOELECTRON SPECTROSCOPY AND AUGER ELECTRON SPECTROSCOPY Turner N H; Schreifels J A Washington G.,University; Fairfax,George Mason University This fundamental review is on the subject of X-ray photoelectron spectroscopy (XPS), also called electron spectroscopy for chemical analysis (ESCA), and Auger electron spectroscopy (AES) and covers articles published in Chemical Abstracts between October 1997 and October 1999. XPS and AES are used widely for the analysis of surfaces. From about 1970 to the present time, these techniques have grown in acceptance by the scientific community. 243 refs.

CHINA

USA

Accession no.786485

Accession no.783747

Item 103 Farbe und Lack 106, No.8, 2000, p.30-4

Item 106 Analytical Chemistry 72, No.12, 15th June 2000, p.71R-9R

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References and Abstracts

INFRARED SPECTROSCOPY Gillie J K; Hochlowski J; Arbuckle-Keil G A Applied Extrusion Technologies Inc.; Abbott Laboratories; Rutgers,University This review on IR spectroscopy highlights three areas in which it has become increasingly important during the last two years. These areas are two-dimensional infrared (2D IR) spectroscopy, combinatorial chemistry and human health. This trend is quite evident in the abstracts examined. The review is focused on articles published during 1998 and 1999, but occasionally includes articles from earlier work if they provide additional information. 148 refs. USA

Accession no.783746 Item 107 Analytical Chemistry 72, No.12, 15th June 2000, p.1R-7R SOLID-STATE NUCLEAR MAGNETIC RESONANCE Dybowski C; Bai S Delaware,University Developments and applications in the field of NMR spectroscopy of solids appearing in the literature between October 1997 and October 1999 are reviewed. Applications of NMR spectroscopy to liquids and solutions are not included. 191 refs. USA

Accession no.783744 Item 108 ACS Polymeric Materials: Science & Engineering.Spring Meeting 2000.Volume 82.Conference proceedings. San Francisco, Ca., 26th-30th March 2000, p.270-1 CHARACTERIZATION OF POLYMER-CLAY NANOCOMPOSITES: XRD VS. TEM Morgan A B; Gilman J W; Jackson C L US,National Institute of Standards & Technology; NIST,Polymers Div. (ACS,Div.of Polymeric Materials Science & Engng.) Novolac-based cyanate ester/clay nanocomposites were prepared using a variety of organically treated clays. The original d-spacing of the clays was determined using Xray diffraction (XRD), and XRD studies were also made on the cured resins. Transmission electron microscopy (TEM) detected undispersed clay tactoids with tightly packed, disordered layers in systems exhibiting no diffraction patterns. The absence of an XRD signal was attributed to the disorder. It was concluded that the drawbacks of XRD for polymer-clay nanocomposite characterisation were order dependence and the inability to differentiate between types of dispersions, whilst the benefits were ease of analysis and the ability to accurately

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measure the d-spacings between clay layers. The benefit of TEM is the ability to solve some of the XRD shortcomings, but the technique is unable to precisely determine d-spacings, and sample preparation and analysis are labour intensive. 6 refs. USA

Accession no.783151 Item 109 International Journal of Polymeric Materials 43, Nos.1-2, 1999, p.105-14. NOVEL EPOXY BASED POLYAMIDES Baraiya R A; Raval D K; Thakkar J R Sardar Patel University Preparation of novel epoxy resin based polyamides was carried out by condensation of biester derivatives, 1,1'(1-methylethylidene)bis(4-(1-(1imino-3-ethylbenzoate)2-propanolyloxy))benzene, with various aliphatic diamines. The resultant epoxy resin polyamides were characterised, and their thermal stability assessed by thermogravimetric analysis. 14 refs. INDIA

Accession no.783026 Item 110 Polymer 41, No.18, 2000, p.6981-6 ALTERATION OF POLYUREA HARD DOMAIN MORPHOLOGY BY DIETHANOL AMINE (DEOA) IN MOLDED FLEXIBLE POLYURETHANE FOAMS Kaushiva B D; Wilkes G L Virginia,Polytechnic Institute & State University Tapping mode atomic force microscopy and small angle X-ray scattering studies showed that the use of the commercially used crosslinking agent, diethanolamine (DEOA), in the formulation of moulded flexible PU foams affected the morphology of the solid state. DEOA was found to disrupt the formation of long (about 100 nm) lamella-like polyurea hard domains. It also disrupted the formation of a consistent distribution of polyurea aggregates (about 50 nm in diameter) and instead produced a finer dispersion of isotropic hard domains (about 5 nm). Adding DEOA therefore reduced the hard domain interconnectivity and this may lead to the reduced solid state modulus (stiffness) which has been previously reported. 10 refs. USA

Accession no.782255 Item 111 Polymer 41, No.18, 2000, p.6787-96 INVESTIGATION OF HYDROTHERMAL AGEING OF A FILLED RUBBER TOUGHENED

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References and Abstracts

EPOXY RESIN USING DYNAMIC MECHANICAL THERMAL ANALYSIS AND DIELECTRIC SPECTROSCOPY Ivanova K I; Pethrick R A; Affrossman S Strathclyde,University The effect of hydrothermal cycling was studied on the water absorption behaviour of a rubber toughened bisphenol A diglycidyl ether-based epoxy resin, filled with silica and cured with dicyandiamide. The results showed that although the saturation water uptake for the samples tested was independent of the hydrothermal history, the equilibrium value of the mass on desorption did depend on the hydrothermal history. Deviations from simple Fickian behaviour were noted for samples which had undergone a previous absorption-desorption cycle. This indicated that water was absorbed in the polar rubbery phase and was not easily released on dehydration. Dielectric spectroscopy showed that the epoxy resin had a heterophasic structure. This was consistent with the suggestion that, while initial water absorption occurred reversibly in the epoxy matrix, subsequent absorption of water into the polar rubbery phase was irreversible at 50C (the temperature used in the study). 35 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.782232 Item 112 Polymer Testing 19, No.4, 2000, p.415-7 CHARACTERIZATION OF POLYEPICHLOROHYDRIN AND COPOLYMERS OF EPICHLOROHYDRINGYLICIDYL ETHERS BY IR SPECTROSCOPY Glavcheev I; Sirashki G; Mateva R Sofia,University of Chemical Technology & Metallurgy; Svistov,D.Tsenov Economic University A study of the possibilities of using infra red spectra for the characterisation of H-bonds formed as the result of macromolecular interactions and the most suitable absorbencies to be used for qualitative and quantitative calculation used epichlorohydrin, phenylglycidyl ether and butylglycidyl ether as its basis. A good agreement between chemical structure, oxygen atom content and calculated H-bonds was found using IR spectra. 7 refs. BULGARIA; EASTERN EUROPE

Accession no.779577 Item 113 Macromolecular Chemistry & Physics 201, No.6, 14th April 2000, p.694-8 MATRIX-ASSISTED LASER DESORPTION IONIZATION TIME-OF-FLIGHT MASS SPECTROSCOPY OF POLYDIMETHYLSIOXANES PREPARED VIA ANIONIC RING-OPENING POLYMERIZATION

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Haddleton D M; Bon S A F; Robinson K L; Emery N J; Moss I Warwick,University; Dow Corning The molecular weight distributions of polydimethylsiloxanes, obtained by the anionic ring-opening polymerisation of hexamethylcyclotrisiloxane initiated by butyllithium in THF, were analysed using MALDI-TOF mass spectroscopy and size exclusion chromatography. The two methods gave molecular weight distributions. The MALDI spectra underestimated the contribution of the higher mass macromolecules, thereby underestimating the average molecular weights. However, the MALDITOF results yielded quantitative information about the polymerisation mechanism and side reactions and these were discussed. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.777890 Item 114 Journal of Adhesion 71, No.4, 1999, p.377-94 SOLID STATE NMR STUDIES OF POLYMERIC DIPHENYLMETHANE DIISOCYANATE (PMDI) DERIVED SPECIES IN WOOD Bao S; Daunch W A; Sun Y; Rinaldi P L; Marcinko J J; Phanopoulos C Akron,University; ICI Polyurethanes 15N variable table contact time (VCT) cross polarisation magic angle spinning (CPMAS) NMR experiments are employed to investigate the reaction products formed in wood composites bonded with 15 N-enriched polymeric diphenylmethane diisocyanate adhesives. Two wood species are studied, Aspen (Populus tremuloides) and Southern Pine (Pinus sylvestris). The influence of temperature and wood moisture content on the distribution of PMDI-derived species are presented and discussed. 13 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; UK; USA; WESTERN EUROPE

Accession no.776674 Item 115 Journal of Applied Polymer Science 76, No.13, 24th June 2000, p.1940-6 B-STAGE CHARACTERISATION OF O-CRESOL NOVOLAC EPOXY RESIN SYSTEM USING RAMAN SPECTROSCOPY AND MATRIXASSISTED LASER DESORPTION/IONISATION MASS SPECTROMETRY Kim W G; Kim H S Seokyeong,University; LG Chemical Ltd. The B-stage of the o-cresol novolac epoxy resin-phenol novolac hardener-triphenylphosphine (TPP) catalyst system is characterised using Raman spectroscopy and matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry. The consistent decreasing intensities of

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References and Abstracts

characteristic epoxy resin peaks in MALDI mass and Raman spectra according to the melt mixing time are observed, which is due to the formation of the epoxyphenol-TPP complex and the propagation reaction between them and with another epoxy resin. The microscopic analysis method provides a useful tool to control the optimum condition of the melt mixing process in the B-stage. 18 refs. KOREA

Accession no.776015 Item 116 Polymer 41, No.13, 2000, p.4793-802 CHARACTERIZATION OF POLYIMIDE GELS CROSSLINKED WITH HEXAMETHYLENE DIISOCYANATE He J; Horie K; Yokata R Tokyo,University; Japan,Institute of Space & Astronautical Science Gels prepared from soluble high-performance fluorine containing polyimides based on 4,4'-(hexafluoroisopropylindene)diphthalic anhydride and 3,3'-dihydroxy4,4'-diaminobiphenyl crosslinked with hexamethylene diisocyanate have been characterised. Static laser light scattering measurements were used to determine weightaverage molecular weight. Equilibrium swelling was also determined and a concentration-dependent form of the Flory-Huggins parameter applied. Results from classical and improved Flory-Rehner theory have been compared. 35 refs. JAPAN

Accession no.774633 Item 117 Journal of Applied Polymer Science 75, No.6, 7th Feb.2000, p. 754-65 CURING OF UF RESINS STUDIED BY LOWRESOLUTION 1H-NMR Root A; Soriano P Neste Oy Technology Centre Low resolution 1 H-NMR was used to study the curing of a series of UF resins and one MUF resin. In addition to following the resin cure it was found that cure rate was dependent upon the methylol group concentration. Postcuring effects were also studied and it was found that the properties of the resin depended upon the amount of water remaining in the resin. It was concluded that low resolution 1H-NMR provides a useful tool for studying cure phenomena in UF resins. 13 refs. EUROPEAN UNION; FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.769017 Item 118 European Coatings Journal

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No.4, April 2000, p.64/77 EVALUATION OF SILICONIZED EPOXY COATINGS BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY Anada Kumar S A; Alagar M; Mahesh K P O; Sankara Narayanan T S N; Mohan V Anna,University Solvent free siloxane modified epoxy coatings were developed by interpenetrating technique. The corrosion resistant behaviour of all siliconised epoxy coating systems with 25% zinc powder cured with four different curatives has been investigated by electrochemical impedance spectroscopy. The results are comparable with those obtained from neutral salt spray tests. The siloxane (10%) modified epoxy coating system “A” with 25% zinc powder cured by hexamethylene diamine offers maximum corrosion protection to steel surfaces. 25 refs. INDIA

Accession no.768536 Item 119 Macromolecules 33, No.2, 25th Jan.2000, p.438-43 MONITORING OF CURING OF POLYURETHANE POLYMERS WITH FLUORESCENCE METHOD Vatanparast R; Li S; Hakala K; Lemmetyinen H Tampere,University of Technology Using nine fluorescence probes, the fluorescence technique was evaluated as a means of monitoring the curing of polyurethanes. The fluorescence emission bands of the probes exhibited hipsochromic shifts as curing progressed. A method was developed to determine the degree of curing based upon the ratio of the low to high intensity changes in the emission bands. The method, which was independent of both probes and polymer, allowed the monitoring of the polymer structure throughout the curing process. 21 refs. EUROPEAN UNION; FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.767568 Item 120 Adhesion ’99. Conference Proceedings. Cambridge, UK, 15th-17th Sept.1999, p.369-73 INTERPHASE CHEMISTRY OF CARBON FIBRE COMPOSITE MATERIALS Prickett A C; Vickers P E; Smith P A; Watts J F Surrey,University (IOM Communications Ltd.) The fibre-matrix interface in carbon fibre-reinforced epoxy resin composites was studied by time of flight secondary ion mass spectrometry (ToF-SIMS) using novel preparation techniques. The initial adsorption between uncured resin or amine curing agent and the fibre was investigated by the use of adsorption isotherms obtained

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References and Abstracts

by the analysis of fibre surfaces following immersion in liquid solutions of the resin. The intact interphase of a composite could be examined by ToF-SIMS following mode I or mode II failure within the spectrometer by the use of carefully designed in-situ fracture stages. 11 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.765326 Item 121 International Polymer Science and Technology 26, No.8, p.T/96-T/102 (Translation of Polimery, Tworzywa Wielkoczasteczkowe, No.5, 1999, p.326) USE OF NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY IN STRUCTURAL INVESTIGATIONS OF CROSSLINKED POLYESTERS Grobelny J A study is reported which sets out to determine the structural changes accompanying the crosslinking of mixed unsaturated polyesters as a function of their chemical composition on the basis of results of studies using high-resolution solid-state nuclear magnetic resonance spectroscopy. It was found that the composition of mixed unsaturated polyesters has an effect on the relaxation behaviour of the crosslinked polymers subsequently obtained from them. An attempt was made to separate the effect associated with the variable content of diol components, and the effect of the formation of a copolymer with styrene. The value of the resultant crosslinking effect under predetermined conditions is determined exclusively by changes in the crosslink density controlled by selecting the composition of the unsaturated prepolymers. 30 refs. EASTERN EUROPE; POLAND

Accession no.764662 Item 122 Polymer 41, No.5, March 2000, p.1731-9 IN-SITU MEASUREMENT OF THE CRYSTALLISATION PROCESS OF POLYCARBONATE/EPOXY RESIN BY A PHOTORESISTOR Li Y S; Chang F C Taiwan,National Chiao Tung University Polycarbonate (10g of Calibre 201-15 from Dow) was mixed with epoxy resin (4g of DER 332 from Dow) in dichloromethane. The solvent was removed and the crystallisation of polycarbonate was monitored by means of a photoresistor (the resistance was lowest when incident light was strongest). In the beginning of annealing, the change of resistance was insignificant when the crystallisation was still at the induction stage. Then the increasing number and size of spherulites scattered the incoming light and the resistance increased quickly. Finally

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the concentration of amorphous polycarbonate decreased and the increasing rate of resistance slowed down. X-ray diffraction patterns showed an ordered polycarbonate structure in the induction period and this converted to amorphous and spherulite structures. DSC data confirmed the validity of the photoresistor method for both primary and secondary crystallisation. The experimental results show good correlation with the Avrami model and the highest crystallisation rate was obtained at 80C. Thermodynamic factors control the crystallisation rate at higher annealing temperatures, while kinetic factors dominate at lower annealing temperatures. 12 refs. TAIWAN

Accession no.764001 Item 123 Composites Part A: Applied Science and Manufacturing 31A, No.2, 2000, p.165-71 FAILURE PHENOMENA IN TWODIMENSIONAL MULTI-FIBRE MICROCOMPOSITES. PART IV: A RAMAN SPECTRASCOPIC STUDY ON THE INFLUENCE OF THE MATRIX YIELD STRESS ON STRESS CONCENTRATIONS van den Heuval P W J; Peijs T; Young R J Eindhoven,University of Technology; UMIST; Queen Mary & Westfield College Raman spectroscopy is used to study the influence of shear yield stress of the matrix on stress situations in carbon fibre/epoxy resin composites containing a planar fibre array. A mixture of two curing agents, with different functionality and molecular weights, are used to cure the epoxy resin in order to obtain a matrix with varying crosslinked density. The carbon fibres are surface treated to give good fibre-matrix adhesion. Three matrix systems are investigated in the study, each with a different yield stress. The mechanical properties of each material are measured under tension and shear conditions. 35 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; UK; WESTERN EUROPE

Accession no.763633 Item 124 Polymers for Advanced Technologies 10, No.11, Nov.1999, p.637-46 CURE BEHAVIOR AND THERMAL DEGRADATION MECHANISMS OF EPOXY AND EPOXY-CYANATE RESINS Regnier N; Fayos M; Moreau P; Lafontaine E; Mortaigne B Arcueil,Centre Technique The curing reaction of tetraglycidyl methylene diamine epoxy cured with tetra-substituted aromatic diamine, and the curing reactions of bisphenol A diglycidyl ether and of tetrabromobisphenol A diglycidyl ether epoxies cured

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References and Abstracts

with methylene bisphenyl-4-cyanate were studied. FTIR spectroscopy of the epoxy system showed that all the epoxy groups had reacted, but not all the primary aromatic amine functions. For the epoxy-cyanate system, the cyanate groups cyclotrimerised to form a crosslinked triazine network and then the epoxy monomers homopolymerised or reacted with the remaining cyanate functions. Thermal degradation studies showed that the epoxy polymer underwent dehydration of the epoxy network and decomposition of the amine structure. The epoxy-cyanate network was less affected than the epoxy polymer. The triazine structure was moderately transformed and the oxazolidone structure was also modified. 15 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.763579 Item 125 Macromolecules 32, No.18, 7th Sept.1999, p.5925-33 DEGRADATION OF POLYMER COATING SYSTEMS STUDIED BY POSITRON ANNIHILATION SPECTROSCOPY. 3. WAVELENGTH DEPENDENCE OF UV IRRADIATION EFFECT Cao H; Yuan J-P; Zhang R; Huang C-M; He Y; Sandreczki T C; Jean Y C; Nielsen B; Suzuki R; Ohdaira T Missouri-Kansas City,University; Brookhaven National Laboratory; Tsukuba,Electrotechnical Laboratory

Glavchev I; Petrova K; Devedjiev I Sofia,University of Chemical Technology & Metallurgy; Bulgarian Academy of Sciences The rate of evaporation of solvents from epoxy coatings obtained from solutions of epoxy oligomers based on bisphenol A with molecular weights of 600 and 2500 were studied. The rate of evaporation was found to depend on the type of solvent, the molecular weights of the oligomers and the possible formation of hydrogen bonds. The formation of hydrogen bonds was investigated using UV and IR spectroscopies of the solutions and coatings. The results were discussed. 5 refs. BULGARIA; EASTERN EUROPE

Accession no.760943 Item 127 Journal of Adhesion Science and Technology 13, No.11, 1999, p.1295-306 MASS SPECTROMETRIC ANALYSIS OF AN EPOXY PHENOLIC ADHESIVE IN THE BULK AS WELL AS IN CONTACT WITH A METAL SURFACE Zaitsev A L; Pleskachevsky Y M Belarus Academy of Sciences

JAPAN; USA

The chemical composition of low molecular weight products of polycondensation during the curing of an epoxy-phenolic adhesive both in the bulk and in a thin layer in contact with a metal is studied using pyrolitic mass spectrometry. It is found that the volatile products from the adhesive bulk differs greatly from those released from the thin oligomer layer bordering the metal surface. The difference in chemical composition of the polycondensation products near the metal surface compared with those in the bulk is related to simultaneously occurring thermal desorption of metal gases from the metal surface. Due to the dissolution of desorption products in the uncured adhesive surface layer, a change is observed in the process of direction of polycondensation and in the chemical composition of the thin sub-surface adhesive layer. The greatest effect on the adhesive surface layer structure and properties is exerted by the carbon mono- and di-oxides desorbed from the metal. The metal surface serves as a catalyst for carboxylation and carbonylation taking place near the interface. Thermodesorption of physically and chemically adsorbed molecules and the competing process of solvent absorption by metal structural defects are the possible causes for the onset of microdefects in the epoxy-phenolic adhesive layers contacting the metal. 14 refs.

Accession no.761282

RUSSIA

Item 126 Polymer Testing 19, No.1, 2000, p.111-4 INVESTIGATION OF SOLVENT INTERACTION IN EPOXY COATINGS

Item 128 Revista de Plasticos Modernos 78, No.519, Sept.1999, p.245-51 Spanish

The photodegradation of a polyurethane coating was studied using accelerated UV irradiation at three different wavelengths, 340, 313 and 800-900 (Xe lamp) nm. Doppler-broadened energy spectra (DBES) and positron annihilation lifetime spectroscopy (PAL) were measured as a function of incident positron energy (0-30 keV) and irradiation time (0-800 hr). Results showed a decrease of free volume and holes at the atomic level during degradation. The UV irradiation effects were found to be strongly wavelength dependent: the photodegradation effect at 313nm was twice as strong as that at 340nm; the effects of the shorter wavelength attenuate with larger extinction coefficient when approaching the bulk; the effects due to the shorter wavelength reach saturation much faster than those from normal sunlight. Both DBES and PAL were shown to be sensitive tools to characterise the depth profile of microstructural changes in polymeric coating materials. 19 refs.

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Accession no.760200

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References and Abstracts

APPLICATION OF FOURIER TRANSFORM INFRARED SPECTROSCOPY TO THE STUDY OF POLYURETHANE COATINGS Irusta L; Fernandez-Berridi M J Pais Vasco,Universidad Fourier transform IR spectroscopy was used in the structural characterisation of a series of segmented polyether- and polyester-urethanes produced using different isocyanates, providing information of use in determining the chemical structure of PU coatings. Modifications occurring in commercial PU coatings exposed to UV radiation were studied by photoacoustic Fourier transform IR spectroscopy. 18 refs. BAYER AG EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; SPAIN; WESTERN EUROPE

Accession no.758781 Item 129 New York, N.Y., Plenum Press, 1997, pp.332. 105.00. 9T ANALYSIS AND DEFORMULATION OF POLYMERIC MATERIALS Gooch J W Designed for the chemist, formulator, student, teacher, forensic scientist, or others wishing to investigate the composition of polymeric materials, the information supplied is intended to provide the necessary working knowledge to analyse, characterise and deformulate materials. An introduction to analysis and deformulation is included, describing the analytical methods and their applications. Accession no.758284 Item 130 Polymer Degradation and Stability 66, No.1, 1999, p.17-22 TRAPPING AND IDENTIFICATION OF VOLATILE PHOTO-PRODUCTS OF A PHOTOOXIDISED EPOXY MATRIX Monay L; Bole J; Dubois C; Chambaudet A Franche-Comte,Universite An organic matrix was synthesised by crosslinking a diglycidyl ether type epoxy resin from bisphenol A with methyltetrahydrophthalic anhydride. The crosslinking reaction was initiated by an accelerator (Nmethylimidazole). A photooxidation chamber was designed to trap and analyse the volatile photooxidation products of this material. The chamber was put into an artificial light ageing cell and linked to a gas chromatograph-mass spectrometer instrument. The photooxidation mechanisms leading to the ablation of the epoxy matrix were identified and discussed. 14 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

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Item 131 Polymer International 48, No.10, Oct.1999, p.1042-5 EFFECTS OF UV RADIATION ON SEVERAL HIGH-PERFORMANCE POLYIMIDE COMPOSITES Kiefer R L; Herring K; Wylie B J; Orwoll R A; Thibeault S A Williamsburg,College of William & Mary; NASA Langley Research Center Three carbon fibre-reinforced polyimides were exposed to UV radiation at 177C, at three different intensities for three different times, so that the product of intensity and time was a constant. Intensities of 1, 2 and 3 suns, where one sun is the power in space at one earth-sun distance, were used, for a time periods of 500, 250 and 167 h. The samples were characterised by X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis, thermomechanical analysis and dynamic mechanical analysis. Measurement of bulk properties showed no difference between samples exposed to heat and UV radiation, and control samples. Surface analysis by XPS showed an apparent decrease in carbonyl concentration on the surface of some exposed samples. This was correlated to surface contamination by a silicone-containing material. 3 refs. USA

Accession no.756185 Item 132 Journal of Applied Polymer Science 74, No.11, 9th Dec.1999, p.2703-15 KINETIC STUDY OF PHENOLIC RESIN CURE BY IR SPECTROSCOPY Carotenuto G; Nicolais L Naples,University Fourier transform infra red spectroscopy was used to study the cure reaction and reaction kinetics of a commercial phenolic resin, using IR spectra in the absorbance mode. It was found that below 140 deg. centigrade that the kinetics of the reaction followed the Jander kinetic model and that a diffusive mechanism was in control. Above 140 deg.C a homogenous first order reaction model best described the reaction, as indicated by analysis using integral methods on the isothermal data. Other models tested, including diffusion controlled reactions, nucleation and growth kinetics and phase boundary movement did not fit the observed data as well as the first order homogenous model. A proposal for a mechanistic model for the resol cure at temperatures greater than 140 deg.C is made. 34 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.756012 Item 133 Polyurethanes Expo ’99. Conference proceedings. Orlando, Fl., 12th-15th Sept.1999, p.303-11

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References and Abstracts

FIBRE OPTIC FTIR: A NOVEL PUR/PIR CATALYST DEVELOPMENT TOOL McDaniel P L; Johnson G L; Kniss J G; Sabram K A Air Products & Chemicals Inc. (American Plastics Council,Alliance for the Polyurethanes Industry) Development of new catalysts promoting different phases of PU foam formation (blowing, gelling, crosslinking) is typically done using a series of physical and handmix generated reactivity profile properties. The ability to understand the evolution of chemical species associated with rigid PU/polyisocyanurate (PUR/PIR) foam formation has been historically only inferred based on their final distribution in the fully cured foam using FTIR or solid state carbon-13 NMR. Neither technique gives insight into the reactions as they occur. Recently, the use of IR transmitting optical fibres as evanescent wave sensors and a mathematical deconvolution technique (iterative target transformation factor analysis) to extract and follow the isocyanate, urea, urethane and trimer concentrations as they occur in both lab scale and machine scale foam production have been refined. The fibre optic probe used can be placed at specific locations within the growing foam to target the evolution of isocyanate chemistries at the surface or core of the foam. The specificity of the technique, speed of data acquisition and portability of equipment all make this method ideal as a tool to fundamentally probe how catalysts alter the distribution of individual chemical species during the initial moments in foam formation. Its utility in understanding the mechanism whereby a novel new catalyst, Polycat 48, improves dimensional stability in a HCFC-141b blown appliance formulation, is demonstrated. The fibre optic FTIR results for Polycat 48 are contrasted to a control catalyst blend of Polycat 5 and Polycat 41 in the same formulation. 10 refs. USA

Accession no.755697 Item 134 Journal of Applied Polymer Science 74, No.10, 5th Dec.1999, p.2432-8 CHARACTERIZATION OF BISPHENOL ABASED EPOXY RESINS BY HPLC, GPC, GPCMALLS, VPO, VISCOMETRY, AND END GROUP ANALYSIS: ON THE IDENTIFICATION OF 2,3DIHYDROXYPROPYL-CONTAINING COMPOUNDS, DETERMINATION OF MOLAR MASS DISTRIBUTION, AND BRANCHING Podzimek S; Kastanek A SYNPO Results of the above characterisation are presented and discussed with particular reference to determination of alpha-glycol-containing compounds, determination of molar mass and molar mass distribution, determination of branching and determination of refractive index increment. 19 refs. CZECH REPUBLIC

Accession no.755647

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Item 135 Polymers for Advanced Technologies 10, No.4, April 1999, p.237-43 CHARACTERISATION OF THE SURFACE OF BULK-MOULDED COMPOUNDS Vallat M F; Schultz J; Mauzac C; Jacquin M Institut de Chimie des Surfaces et Interfaces; PSA Etudes et Recherches Centre Technique de Belchamp The surface characterisation of bulk moulding compound (BMC) automotive parts using complementary techniques of surface analysis, i.e. SEM, X-ray photoelectron spectroscopy, time of flight secondary ion mass spectroscopy, glow discharge spectroscopy and contact angle is described. Similarities and differences between BMC surfaces and sheet moulding compound (SMC) surfaces are pointed out. Particular emphasis is placed on mould release agents (polymeric and stearate) on the surface which can influence future bonding behaviour. 14 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.754736 Item 136 Progress in Organic Coatings 36, Nos.1-2, 1999, p.34-8 MECHANISM OF ACID RAIN ETCHING OF ACRYLIC-MELAMINE COATINGS Mori K; Tachi K; Muramatsu M; Torita K Toyota Central R & D Laboratories Inc.; Toyota Motor Corp. The etching of automotive coatings by acid rain was studied by immersing acrylic-melamine coatings in 70 wt% sulphuric acid at 60 C, and determining the sulphuric acid distribution within the coatings using electron probe microanalysis. The region containing the acid had a distinct boundary which expanded at a constant rate. The acid extracted water-insoluble melamine derivatives, the extraction rate being proportional to the permeation rate. It was concluded that etching was caused by the extraction of the water-insoluble derivatives by the sulphuric acid, and that the diffusion of sulphuric acid at the boundary was controlled by hydrolysis of crosslinks. 3 refs. JAPAN

Accession no.753429 Item 137 Progress in Organic Coatings 36, Nos.1-2, 1999, p.1-10 PYROLYSIS GAS CHROMATOGRAPHY OF COATING MATERIALS - A BIBLIOGRAPHY Haken J K New South Wales,University An extensive bibliography on the pyrolysis gas chromatography of coating materials is given, including the analysis of homopolymers and copolymers, and of

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microstructure and end groups. Separate tabulations are provided for references related to pyrolytic alkylation and reactive degradation. 491 refs. AUSTRALIA

Accession no.753426 Item 138 Journal of Applied Polymer Science 74,No.3, 17th Oct.1999, p.532-40 TETRAFUNCTIONAL EPOXY RESINS:MODELING THE CURING KINETICS BASED ON FTIR SPECTROSCOPY DATA Musto P; Martuscelli E; Ragosta G; Russo P; Villano P Italy,National Research Council The curing kinetics of two thermosetting systems based on a tetrafunctional epoxy resin are investigated by Fourier transform infrared spectroscopy. Two formulations are studied, in which the hardener is an aromatic diamine and a carboxylic dianhydride, respectively. The quantitative evaluation of the epoxy conversion is based on spectra collected in the nearinfrared range (8000-4000 cm -1) as well as in the medium IR range (4000-400 cm -1). The kinetic parameters evaluated in the above frequency intervals are significantly different. The reasons for such a discrepancy are critically discussed. Several kinetic models, based on the widely employed Kamal approach, are applied to verify their predictive capability. Satisfactory results are obtained for the amine-cured system, particularly with a modified equation taking into account the autocatalytic nature of the process as well as a limiting diffusional effect. Less accurate results are achieved for the anhydride-cured system. 23 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.752308 Item 139 Journal of Macromolecular Science C 39, No.3, 1999, p.405-44 STRUCTURAL INVESTIGATIONS OF UNSATURATED AND CROSS-LINKED POLYESTERS BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY Grobelny J Polish Academy of Sciences A review of the literature on the above is presented. Particular attention is paid to compositional sequence distribution in unsaturated polyesters as revealed by solution-state carbon13 NMR spectroscopy, solution-state carbon-13 NMR study of the maleate (cis)-fumarate (trans) isomerism in unsaturated polyesters and related compounds, and high-resolution solidstate carbon-13 NMR structural investigations of crosslinked polyesters. 56 refs. EASTERN EUROPE; POLAND

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Item 140 Journal of Applied Polymer Science 73, No.8, 22nd Aug.1999, p1569-77 UV CURING OF SURFACE COATING SYSTEM CONSISTING OF CYCLOALIPHATIC DIEPOXIDE-ENR-GLYCIDYL METHACRYLATE BY CATIONIC PHOTOINITIATORSCHARACTERIZATION OF THE CURED FILM BY FTIR SPECTROSCOPY Kumar R N; Woo C K; Abusamah A Malaysia,Science University Films were cast from a system consisting of a cycloaliphatic diepoxide, epoxidised natural rubber (ENR), glycidyl methacrylate (GMA) and a cationic photoinitiator, triphenylsulphonium hexafluoroantimonate. The films were cured by UV radiation, and characterised using Fourier transform infrared spectroscopy. It was determined that the acrylic double bonds, the epoxy groups of GMA, the isoprene double bonds, the epoxy groups of ENR, and the epoxy groups of the cycloaliphatic epoxide resin all participated in the photoinitiated polymerisation and crosslinking reactions resulting in an interpenetrating polymer network. 21 refs. MALAYSIA

Accession no.744182 Item 141 Analytical Chemistry 71, No.12, 15th June 1999, p.121R-180R PROCESS ANALYTICAL CHEMISTRY Workman J; Veltkamp D J; Doherty S; Anderson B B; Creasy K E; Koch M; Tatera J F; Robinson A L; Bond L; Burgess L W; Bokerman G N; Ullman A H; Darsey G P; Mozayeni F; Bamberger J A; Greenwood M S Kimberly-Clark Corp.; Washington,University; Monsanto Co.; Westinghouse Savannah River Co.; AlliedSignal Inc.; Dow Corning Corp.; Pacific Northwest National Laboratory; Procter & Gamble Co.; Akzo Nobel Chemicals Inc. An in-depth review is presented of process analytical chemistry covering the period 1994 to 1999. Sections are included on sampling systems, chromatography, nearinfrared and IR spectroscopy and imaging, Raman spectroscopy, electronic spectroscopy (UV-visible and fluorescence), mass spectrometry, chemometrics, flow and sequential injection analysis and ultrasonic analysis. 1303 refs. USA

Accession no.741310 Item 142 Analytical Chemistry 71, No.12, 15th June 1999, p.61R-80R ANALYSIS OF SYNTHETIC POLYMERS AND RUBBERS

© Copyright 2003 Rapra Technology Limited

References and Abstracts

Smith P B; Pasztor A J; McKelvey M L; Meunier D M; Froelicher S W; Wang F C-Y Dow Chemical Co. Methods for characterising rubbers, synthetic polymers and blends are reviewed mostly over the period from October 1996 to October 1998. Methods covered include pyrolysis gas chromatography, liquid chromatography, mass spectrometry, NMR spectroscopy, thermal analysis, IR spectroscopy and Raman spectroscopy. 495 refs. USA

Accession no.741309 Item 143 Analytical Chemistry 71, No.12, 15th June 1999, p.21R-32R COATINGS Anderson D G Witco Corp. A review of techniques for analysing coatings, raw materials for coatings and substrates to be coated is presented for the period 1996 to 1998. Analytical techniques covered include gas chromatography, GPC, HPLC, IR spectroscopy, NMR spectroscopy, surface analysis, UV-visible spectroscopy, microscopy, thermal analysis and procedures relating to aspects of environmental and industrial hygiene. 295 refs. USA

Accession no.741308 Item 144 ACS Polymeric Materials Science & Engineering.Volume 80.Conference proceedings. Anaheim, Ca., Spring 1999, p.320-1.012 DEGRADATION OF POLYMER COATINGS STUDIED BY POSITRON ANNIHILATION SPECTROSCOPY Cao H; Zhang R; Yuan J-P; He Y; Sandreczki T C; Jean Y C; Nielsen B; Suzuki R; Ohdaira T Missouri-Kansas City,University; Brookhaven National Laboratory; Tsukuba,University (ACS,Div.of Polymeric Materials Science & Engng.) The photodegradation of polyurethane coatings under accelerated UV irradiation was studied by investigating physical defects, including free volumes and holes, at the atomic level using Doppler broadening of positron annihilation irradiation and positron annihilation lifetime spectroscopy. There was a significant decrease of free volume fraction with increased duration of irradiation and depth from the surface to the bulk. There was correlation between physical defects (free volume) at atomic level and the chemical defects (free radicals). 4 refs. JAPAN; USA

Accession no.738923

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Item 145 Journal of Applied Polymer Science 73, No.4, 25th July 1999, p.563-71 SOLID-STATE 13C NUCLEAR MAGNETIC RESONANCE STUDY OF CURED, UNSATURATED POLYESTER RESINS Hietalahti K; Root A; Skrifvars M; Sundholm F Helsinki,University; Neste Group; Neste Chemicals R & T The styrene sequence distributions and amount of reacted fumarate units in cured, unsaturated polyester resins were studied by solid-state carbon-13 NMR. It was shown that increasing the styrene content and molar ratio of styrene to the double bonds in the polyester chain increased the amount of diad and n-ad sequences and decreased the amount of monad sequences. At the same time, the amount of reacted fumarate units increased. The Tg was almost constant for resins with the same composition but different styrene contents. Changing the composition affected the Tg, which could not be detected for highly crosslinked resins. The mechanical properties were improved with increasing styrene content. 14 refs. FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.738095 Item 146 Shawbury, Rapra Technology Ltd., 1999, pp.139, 12ins. 12/6/99. Rapra Review Rept.108, vol.9, no.12, 1999. NALOAN CHARACTERISATION OF POLYURETHANES Forrest M J Rapra Technology Ltd. Edited by: Dolbey R (Rapra Technology Ltd.) Rapra.Review Rept.No.108 A review is presented which offers an introduction to polyurethanes and their chemistry, indicating the chemical techniques that are used to characterise their structure, composition, and properties. Additives used in polyurethanes are discussed, which control the reaction chemistry associated with their formation and to modify the properties of the final products. Spectroscopic, chromatographic, thermal techniques, wet chemistry techniques and the use of nitrogen analysers are examined. Characterisation of starting materials and polymer structure and characterisation of additives are discussed, followed by cure reaction studies, failure diagnosis and related issues, and general test methods for PU raw materials and products. 516 refs. This document is available only by purchase from Rapra Technology. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.735659 Item 147 Geneva, 1998, pp.5. NALOAN. ISO 4583-. PLASTICS - EPOXY RESINS AND

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RELATED MATERIALS - DETERMINATION OF EASILY SAPONIFIABLE CHLORINE International Organisation for Standardisation ISO 4583Version 1998. Technically equivalent to DIN 54812 and NFT 51-524. Identical to BS 2782-4:METHOD 433B(1998), BS 2782:PT4:MTD433B(1979), BS EN ISO 4583, EN ISO 4583, NEN ISO 4583. Similar to UNI 8701/ 13. Photocopies and loans of this document are not available from Rapra. WORLD

Accession no.735088 Item 148 Journal of Applied Polymer Science 72, No.7, 16th May 1999, p.913-25 HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY OF EPOXY RESINS Fuchslueger U; Rissler K; Stephan H; Grether H J; Grasserbauer M Ciba Specialty Chemicals Inc.; Vienna,Technical University The application of liquid chromatography coupled to mass spectrometry for the analysis of epoxy resins was shown in two examples. Electrospray (ESI) and atmospheric pressure chemical ionisation (APCI) were compared with respect to the ionisation of diglycidyl ether of bisphenol A (DGEBA)-based epoxy resins. By-products in a typical modified solid DGEBA-based epoxy resin and in a new weatherable crosslinker for powder coating applications were characterised and discussed. 26 refs. AUSTRIA; SWITZERLAND; WESTERN EUROPE

Accession no.734831 Item 149 Antec ’99.Volume 1.Conference proceedings. New York City, 2nd-6th May, 1999, p.930-4.012 STUDY ON THE CURE OF THE SILOXANEMODIFIED EPOXY RESINS Yayun Liu; Martin G C; Zhaohui Meng Syracuse,University (SPE) The curing kinetics and physical properties of siloxanemodified epoxy resins, cured using 2-ethyl-4-methyl imidazole, were studied using differential scanning calorimetry and Fourier transform infrared spectroscopy. The thermal stabilities were evaluated using thermogravimetric analysis, and fracture toughness was measured using double torsion tests. A higher fracture toughness and a rougher fracture surface were observed in the siloxane-modified resin compared with the unmodified material. The modified resins also had better thermal stability and longer pot lives. The curing of the modified resins followed first-order reaction kinetics. 18 refs. USA

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Item 150 Journal of Coatings Technology 71, No.889, Feb.1999, p.71-84 CHARACTERISATION OF INFRARED ABSORPTION BY POWDER COATINGS ON STEEL PANELS Carr W W; Williamson V A; McFarland E G; Johnson M R; Stewart A L; Pasley W E Georgia,Institute of Technology; Southern Company Services Interest in faster curing systems has led to infrared curing of powder coatings. The efficiency of infrared heating depends on both the coating spectral absorption characteristics and the spectral emissions of the infrared source. This detailed article supplies a comprehensive examination of a technique for measuring the spectral absorptivity of powder coatings, and then using the normalised emissions of blackbody emitters to calculate integrated average absorptivity. The effects of several powder coating parameters on spectral absorptivities, integrated average absorptivities, and overall radiant efficiencies are evaluated. Parameters include polymer type, pigment type, film thickness, fillers, curing and gloss. 11 refs. USA

Accession no.726824 Item 151 Shawbury, Rapra Technology Ltd., 1997, pp.315. 220.00. 30cms. 9922 RAPRA COLLECTION OF INFRARED SPECTRA OF RUBBERS, PLASTICS AND THERMOPLASTIC ELASTOMERS. SECOND EDITION Sidwell J A This book provides a set of transmission and pyrolysate spectra of a comprehensive range of technically important rubber and plastics materials including copolymers and blends which are in current use. Materials are indexed under both polymer and trade name. Accession no.725345 Item 152 Gummibereifung 72, No.5, May 1996, p.44/6 German WHAT A SPORTY TYRE MUST HAVE Mutz K A modern and sporty tyre must have one thing above all. It must empathise at a high level of performance. Further aspects are reviewed in detail regarding Michelin’s newly conceived high performance car tyre, the Pilot SX-GT as a successor to the XGT V, as well as Michelin’s top-ofthe-range Pilot model, the SX-MXX2, fitted on the car production assembly line to the Ferrari, McLaren and

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References and Abstracts

Porsche. Discussion is focussed on tread pattern, rubber mixture and optimising tread depth, as well as wet weather performance, traction, braking and cornering. MICHELIN; FERRARI; MCLAREN; PORSCHE EUROPE-GENERAL; EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; GERMANY; WESTERN EUROPE

Accession no.725315 Item 153 International Journal of Polymer Analysis and Characterization 4, No.6, 1998, p.565-78 THERMAL AND NUCLEAR MAGNETIC RESONANCE CHARACTERIZATION OF LINEAR AND RADIAL HIGH PERFORMANCE POLYIMIDES Harruna I I; Petzold O Clark Atlanta University Radially oriented polyimides were prepared based on the geometrically favourable fluorene central unit by condensation of the C-terminus of the linear polyimides. Characterisation of the polymers was achieved by FTIR spectroscopy, proton NMR and carbon-13 NMR spectroscopy, X-ray diffraction, solubility and intrinsic viscosity measurements. Thermal properties were investigated by TGA, DSC and optical polarising microscopy. The radially oriented polyimides were compared with their linear analogues. TGA indicated that linear and radially oriented polyimides were stable up to about 400C in air and under argon atmospheres. 5 refs. (10th International Symposium on Polymer Analysis and Characterization, Toronto, Canada, Aug.1997) USA

Accession no.721932 Item 154 Plaste und Kautschuk 41, No.5, Sept.1994, p.216-20 German UV-CURING EPOXY RESINS AS COATING MATERIALS FOR MICROCHIPS Bittmann E; Ehrenstein G W Friedrich-Alexander University UV curing of resins can be characterised by a special DSC method called photocalorimetry where the heat evolved by the reacting material is registered during the UV irradiation. By varying the components of the resin mixture and the irradiation parameters, the photocalorimetric method was used to determine influencing factors on the curing of an epoxy resin system designed to serve as a coating material for microchips. 7 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.721566

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Item 155 Journal of Adhesion Science and Technology 13, No.3, 1999, p.379-91 DETERMINATION OF THE ADHESION PROPERTIES OF AN ALKYD PIGMENTED COATING BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY Gonzalez J E G; Rosca J C M Gran Canaria,University Impedance measurements were performed in different frequency ranges at open circuit potential for an alkyd coating with titanium dioxide as a mineral pigment in 3% sodium chloride. The most probable impedance equivalent circuit method was considered for data analysis. The interpretation of the impedance spectra permitted the determination of water permeation, the formation of blisters, swelling of the coating, and the loss of adhesion. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.721335 Item 156 ACS Polymeric Materials Science and Engineering.Fall Meeting 1997.Volume 77.Conference proceedings. Washington, D.C., 1997, p.46-7 012 APPLICATION OF SEC AND HPLC TO THE CHARACTERIZATION OF POLYMERS, OLIGOMERS, AND SMALL MOLECULES USED IN COATINGS AND INKS Kuo C; Grieser M D; Robinson D Henkel Corp. (ACS,Div.of Polymeric Materials Science & Engng.) Applications are given of the use of size exclusion chromatography and high performance liquid chromatography for the characterisation of coatings systems which either use water as the major solvent or utilise low molecular weight polymers, oligomers, and reactive additives which are then reacted to produce high molecular weight and crosslinked films. 6 refs. USA

Accession no.720838 Item 157 Macromolecules 32, No.3, 9th Feb.1999, p.690-6 DYNAMIC LIGHT SCATTERING FROM SOLGEL TRANSITION OF UNSATURATED POLYESTER RESINS Lin H L; Yu T L; Cheng C H Taiwan,Yuan-Ze University; Taiwan,National Tsing Hua University Measurements of dynamic light scattering(DLS) and dynamic viscoelasticity were carried out on an unsaturated polyester/styrene system (Eterset 2821) at various degrees of curing through sol-gel transition. The measurements

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were carried out with both polarised and depolarised scattered light. The degrees of conversion at various curing stages were measured by DSC. The experimental results indicated that the depolarised DLS correlation functions were independent of the degree of curing. The polarised DLS data revealed two modes of relaxation before gelation but only one mode of relaxation after gelation. The correlation function of polarised DLS varied with degrees of curing and approached that of depolarised DLS after gelation. Both the DLS and viscoelastic measurements showed the divergence of relaxation times at gelation, indicating the consistency of these two measurements for defining gelation. 39 refs. TAIWAN

Accession no.719320 Item 158 Geneva, 1997, pp.5. ISO 8974-. PLASTICS - PHENOLIC RESINS DETERMINATION OF RESIDUAL PHENOL CONTENT BY GAS CHROMATOGRAPHY International Organization for Standardization ISO 8974Version 1997. Similar to BS 2782:PT4:MTD451R(1995), BS EN ISO 8974, DIN ISO 8974, EN ISO 8974, NEN EN ISO 8974, SS EN ISO 8974 and UNI EN ISO 8974. Photocopies and loans of this document are not available from Rapra. WORLD

Accession no.716565 Item 159 ACS Polymeric Materials Science and Engineering. Fall Meeting 1998. Volume 79. Conference proceedings. Boston, Mas., 23rd-27th Aug.1998, p.396-7. 012 MOLECULAR LEVEL PROCESSES NEAR POLYMER SURFACES AND INTERFACES: MULTI-DIMENSIONAL SPECTROSCOPIC APPROACHES Urban M W North Dakota State University Behaviour of macromolecules near surfaces and interfaces of polymeric thin films and coatings may play a vital role in numerous applications. Therefore, understanding of molecular level processes responsible for durability adhesion, and many other macroscopic processes is of particular importance. Emphasis is placed on stratification processes in multi-component polymeric films, with particular emphasis on polymer-surfactant interactions in latexes and responsiveness of individual components during coalescence of waterborne PUs. The presence of macromolecular arrangements and interactions among various components near the filmair and the film-substrate interfaces can be effectively monitored using attenuated total reflectance and step-

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scan photoacoustic Fourier transform infrared spectroscopy. 22 refs. USA

Accession no.713319 Item 160 ACS Polymeric Materials Science and Engineering. Fall Meeting 1998. Volume 79. Conference proceedings. Boston, Mas., 23rd-27th Aug.1998, p.508. 012 USING NMR FOR STRUCTURE DETERMINATION OF POLYURETHANES Ippoliti J T St.Thomas,University Polyether-urethane materials have been used to insulate long term implantable cardiac pacing leads for many years. In general this material has proven satisfactory, but certain models of pacing leads have had less than desirable clinical performance caused by a degradation of the insulation and eventual exposure of tile underlying conductors. The degradation process seems to be oxidative in nature. A study is undertaken to see if NMR was a suitable tool to study the in vivo degradation of a polyether-urethane material of durometer 80A (P80A). USA

Accession no.713292 Item 161 ACS Polymeric Materials Science and Engineering. Fall Meeting 1998. Volume 79. Conference proceedings. Boston, Mas., 23rd-27th Aug.1998, p.506-7. 012 INFRARED SPECTROSCOPIC STUDY OF OXIDATION IN POLYURETHANE HARD SEGMENTS Skorich S R; Benz M E Medtronic Inc. Previous studies have indicated that in vivo oxidation of polyether urethanes (PEUs) has involved depletion of the soft segment of the material . The use of an attenuated total reflectance (ATR) objective on the infrared (FTIR) microscope has allowed analysis of much smaller areas on PU tubing samples removed from in vivo implantation. By means of the micro ATR, the differences between the IR spectra of clear vs. fissured areas of PEUs are enhanced, and IR peaks typical of fissured areas are observed. Similar peaks were observed on fissured areas of a polycarbonate urethane (PCU) which shares the same hard segment with the PEUs. It became clear that the hard segment was involved in the fissuring process as well as the soft segment. Hard segments in both these materials were based on 4,4'-methylene bis diisocyanate (MDI) and 1,4-butanediol (BDO). Two model diethyl carbamate (urethane) compounds are synthesised from 4,4'methylene dianiline and 4,4'-diaminobenzophenone. The spectra of these materials show the same sort of spectral

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References and Abstracts

differences as between the clear and fissured materials above. These compounds closely model the hard segment of the above materials, and differ only in the oxidation to a carbonyl group of the central methylene group in the molecule. This implies that the same process is occurring in the PU hard segments, in addition to any soft segment reactions. 6 refs. USA

Accession no.713291 Item 162 Polimery Tworzywa Wielkoczasteczkowe 42, No.2, 1997, p.107-10 Polish GAS CHROMATOGRAPHIC DETERMINATION OF FREE FORMALDEHYDE IN RESINS AND PLASTIC PRODUCTS Guberska J; Groman A Moscicki I.,Industrial Chemistry Res.Inst. Two indirect methods are presented for determining free formaldehyde in amine- and phenol-formaldehyde resins in the form of its derivative with 2,4-dinitrophenylhydrazine and after reduction to methanol. 18 refs. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. EASTERN EUROPE; POLAND

Accession no.710818 Item 163 Journal of Materials Science 33, No.18, 15th Sept.1998, p.4595-601 FTIR SPECTROSCOPY AND PHYSICAL PROPERTIES OF AN EPOXY/BISMALEIMIDE IPN SYSTEM Musto P; Martuscelli E; Ragosta G; Russo P; Scarinzi G Italy,National Research Council

SPECTROMICROSCOPY Rightor E; Hitchcock A; Urquhart S; Ade H; Priester R; Lidy W Dow Chemical Co.; McMaster University; North Carolina,State University (SPI,Polyurethane Div.) Microchemical phase segregation phenomena can play a key role influencing physical properties of flexible PUs. A great deal of information has been inferred about the composition and behaviour of phases of interest from indirect methods. However, direct methods for mapping the nature of these phases have been thwarted by the small size of precipitates, radiation sensitivity and the complexity of PU chemistry. With the emerging method of X-ray spectromicroscopy the urea/urethane content of urea precipitates can be mapped, the chemical composition of filler particles determined and imaged, and the influence of additives such as diethanol amine (DEOA) studied. Abstract only. USA

Accession no.708705 Item 165 Polyurethanes Expo ’98. Conference proceedings. Dallas, Tx., 17th-20th Sept.1998, p.695. 43C6 FOURIER TRANSFORM INFRARED (FTIR) CHARACTERISATION OF CHEMICAL AGENT RESISTANT COATINGS (CARC) DURABILITY USING INFRARED (IR) CARDS AND SILICONE WAFERS Lum W; Patterson P; Escarsega J US,Army Research Laboratory (SPI,Polyurethane Div.)

EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Rapid, cost-effective sampling accessories for FTIR analysis are quite suitable with minimum sample preparation in coating materials studies. The US Army’s camouflage, PU topcoat MIL-C-46168 chemical agent resistant coating (CARC) was applied to IR cards and silicon wafers. After curing, the coating’s durability was tested using two separate accelerated weathering techniques (QUV-CON and Xenon-Arc), and as well as two outdoor exposure test methods (South Florida and EMMA(QUA)-NTW). Characterisation of the binder’s chemical changes during both natural and accelerated weathering processes was monitored using FTIR. The experimental results of the coating’s resistance to the accelerated weathering and outdoor exposure conditions were summarised. This abstract includes all the information contained in the original article.

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USA

Item 164 Polyurethanes Expo ’98. Conference proceedings. Dallas, Tx., 17th-20th Sept.1998, p.295-6. 43C6 SUBMICRON CHEMICAL MAPPING OF FLEXIBLE POLYURETHANES BY X-RAY

Item 166 Polymer 40, No.4, Feb.1999, p.1053-6 CHARACTERIZATION OF THE CURING

Blends of a tetrafunctional epoxy resin and a thermosetting bismaleimide resin (BMI) cured with 4,4'diamino diphenyl sulphone were investigated. Information on the conversion of the reactive groups upon curing was obtained by FTIR spectroscopy. Results demonstrated that the addition of BMI improved such properties of the neat epoxy resin as the Tg and the stiffness, while reducing, at the same time, its equilibrium water uptake. 22 refs.

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References and Abstracts

BEHAVIOUR OF CYANIC ESTER BY A POSITRON-ANNIHILATION LIFETIME TECHNIQUE Hayashi T; Nakamura H; Suzuki T Sumitomo Chemical Co.Ltd.; Japan,High Energy Accelerator Research Organisation A positron annihilation lifetime technique was used to study the curing process of a dicyanate resin system. The technique showed that the size of free volumes of the cured resins increased as the curing reaction proceeded. This was supported by the observed decrease in specific gravity and dielectric constant and by an increase in the water pick-up rate with increasing degree of cure. 27 refs. JAPAN

Accession no.707116 Item 167 Polymer Degradation and Stability 61, No.3, 1998, p.543-6 DETECTION OF MONOMERIC HEXANE DIISOCYANATE IN AQUEOUS EXTRACTS OF A POLYURETHANE DEVICE AS AN ARTEFACT OF INJECTION PORT PYROLYSIS IN GAS CHROMATOGRAPHY Treacy J; Lamond P Smith & Nephew Group Research Ltd. Aqueous extractions were carried out on a PU device during stability studies. Analysis of the extracts, reconstituted in THF, showed the presence of free monomeric hexane diisocyanate (HDI) when analysed by gas chromatography with mass spectrometric detection. The detection of HDI in this study was shown to be an artefact resulting from injection port pyrolysis during gas chromatographic analysis. HPLC, which does not impose thermal stress, was used to analyse the same samples to show that HDI was formed as a result of injection port pyrolysis of the polymer. 4 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.701983 Item 168 Journal of Applied Polymer Science 70, No.6, 7th Nov.1998, p.1221-37 PHOTOOXIDATION OF ANHYDRIDE-CURED EPOXIES: FTIR STUDY OF THE MODIFICATIONS OF THE CHEMICAL STRUCTURE Ollier-Dureault; Gosse B Schneider Electric; CNRS-LEMD The photooxidative degradation of anhydride-cured epoxies was studied using transmission Fourier transform infrared and attenuated total reflection spectroscopy. The degradation was heterogeneous, the surface being much more affected from the bulk. Epoxies containing flexibilisers, which were rich in ester groups but

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containing fewer phenyl groups, degraded much more rapidly during the first hours of exposure than those without flexibilisers. After 40 hours of irradiation, the disappearance rate of aromatic groups was dependent only upon their initial concentration, whilst the formation kinetics of hydroxyl groups was determined by the diffusion of oxygen into the material. The formation of hydrophilic products, acids, and alcohols was confirmed by chemical treatment, and it was concluded that their presence and high concentration at the surface could be responsible for the degradation of the insulating properties of epoxies when used as electrical insulators. 20 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.700202 Item 169 Journal of Polymer Science : Polymer Physics Edition 36, No.13, 30th Sept.1998, p.2267-74 MISCIBILITY AND CRYSTALLIZATION BEHAVIOR OF SOLUTION-BLENDED PEEK/PI BLENDS Xiaohua Kong; Hao Tang; Lisong Dong; Fengen Teng; Zhiliu Feng Jilin,University; Changchun,Institute of Applied Chemistry Using two types of polyimide, identified as YS-30 and PEI-E, with the same diamine but different dianhydrides, the miscibility and crystallisation behaviour of solutionblended polyether-etherketone (PEEK)/polyimide (PI) blends were investigated using differential scanning calorimetry, optical microscopy and small angle x-ray scattering. The blends containing YS-30 had a single glass transition temperature over the entire composition range, and were therefore considered to be fully miscible. The crystallisation of PEEK was hindered by the presence of YS-30, the crystallinity decreasing with an increase in the PI content. The dominant morphology was interlamellar. The blends containing PEI-E were immiscible, and there was little change in the crystallisation of PEEK. The spherulitic texture of the blends was dependent upon both the blend composition and molecular structure of the PI which was used. 16 refs. CHINA

Accession no.698258 Item 170 Composites Plastiques Renforces Fibres de Verre Textile No.21, May/June 1997, p.48-54 French DURABILITY OF COMPOSITES: HOW TO ACHIEVE RELIABLE ACCELERATED AGEING Siampiringue N; Gaumet S; Lemaire J Centre National d’Evaluation de Photoprotection The use of accelerated ageing tests and spectrophotometric techniques in studying the

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References and Abstracts

photooxidative degradation of unsaturated polyester resins and glass fibre-reinforced composites is examined. Results of accelerated and natural ageing tests are compared, and criteria to be taken into account in achieving accelerated test results representative of reality are discussed. 5 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.695308 Item 171 Polymer 39, No.25, 1998, p.6489-500 INVESTIGATION OF GLASS TRANSITION BEHAVIOURS IN AROMATIC POLY(AMIC ACID) PRECURSORS WITH VARIOUS CHAIN RIGIDITIES BY OSCILLATING DIFFERENTIAL SCANNING CALORIMETRY Kim S I; Pyo S M; Kim K; Ree M Pohang,University of Science & Technology It is difficult to obtain true glass transition (Tg) values for polyamic acids due to the presence of residual solvents. Successful measurements were made using oscillating differential scanning calorimetry, the residual solvent content being independently determined by proton nuclear magnetic resonance spectroscopy. The measured Tg values were fitted by a modified Gordon-Taylor equation as a function of composition, to give the solvent-free Tg values. The higher the chain rigidity the higher was the Tg. Phase diagrams for the poly(amic acid)/N-methyl-2pyrrolidone system were constructed. 72 refs. KOREA

Accession no.694670 Item 172 Journal of Applied Polymer Science 69, No.11, 12th Sept.1998, p.2175-85 IR SPECTROSCOPY AS A QUANTITATIVE AND PREDICTIVE ANALYSIS METHOD OF PHENOL-FORMALDEHYDE RESOL RESINS Holopainen T; Alvila L; Rainio J; Pakkanen T T Joensuu,University; Dynoresin Oy A set of resin samples was characterised by IR and carbon-13 NMR spectroscopy. The suitability of IR spectroscopy for the quantitative analysis of resins was evaluated by statistical methods using the NMR reference data as calibration. The values of interesting properties, e.g. the amount of free phenol and the formaldehyde-to-phenol molar ratio, of the resins being similar to the calibration resins were predicted from the IR spectra. The predicted results were compared with those observed by carbon-13 NMR spectroscopy. 15 refs. FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.692990

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Item 173 Journal of Applied Polymer Science 69, No.9, 29th Aug.1998, p.1805-12 OPTIMIZING THE CONDITIONS OF QUANTITATIVE CARBON-13 NMR SPECTROSCOPY ANALYSIS FOR PHENOLFORMALDEHYDE RESOL RESINS Luukko P; Alvila L; Holopainen T; Rainio J; Pakkanen T T Joensuu,University; Dynoresin Oy The experimental tine required for carbon-13 NMR quantitative analysis of phenol-formaldehyde resins was reduced so that quantitativeness was maintained. The quantitative spectra of 14 model resins were obtained using a gated decoupling technique suppressing the nuclear Overhauser enhancement. The paramagnetic additive, chromium acetylacetonate, was used to shorten relaxation times of carbon atoms. The use of chromium acetylacetonate was optimised in two deuterated solvents, DMSO and acetone. In order to achieve short relaxation times and increase the measurements times, the concentration of relaxation reagent, the delay time and the number of NMR scans were optimised. Quantitativeness was proved by analysing the spectra of accurate mixtures of model compounds and the spectra of the condensed model resins. 24 refs. FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.692419 Item 174 Antec ’98. Volume II. Conference proceedings. Atlanta, Ga., 26th-30th April 1998, p.2211-4. 012 IDENTIFICATION OF POLYMER PRODUCTS VIA ANALYTICAL PYROLYSIS Wampler T P; Zawodny C P CDS Analytical Inc. (SPE) Gas chromatography is a simple, inexpensive and popular tool for the investigation of organic materials, provided they are volatile within the working temperature range, generally up to about 300 deg.C. Unfortunately, this limitation excludes a class of organic materials which comprises a huge percentage of everyday items polymers. Pyrolysis is a controlled thermal technique which easily extends the applicability of gas chromatography to polymeric materials. Examples include kitchen appliances, textile fibres automotive paints, adhesives, tyre rubber, stationary items, computer parts and artworks from museums. A brief discussion of the chemistry involved is followed by a range of example pyrograms. USA

Accession no.687417 Item 175 New York, N.Y., Wiley-VCH, 1997, pp.xx,298. 70.00. 5/8/98. 91T

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STATIC HEADSPACE-GAS CHROMATOGRAPHY. THEORY AND PRACTICE Kolb B; Ettre L S This book provides a thorough look at the subject of static headspace-gas chromatography. It covers the theory of headspace sampling, describes quantitative calibration techniques and presents detailed methods adapted for automation. Many examples from the most important applications of static HS-GC in environmental analysis, polymers, packaging, pharmaceuticals and food analysis are included. Accession no.686020 Item 176 Acta Polymerica 49, No.6, June 1998, p.272-93 MALDI-TOF MASS SPECTROMETRY IN THE ANALYSIS OF SYNTHETIC POLYMERS Rader H J; Schrepp W Max-Planck-Institut fuer Polymerforschung; BASF AG The principles and instrumental factors influencing spectra in matrix-assisted laser desorption/ionisation spectrometry of synthetic polymers are reviewed in detail. The technique is increasingly applied to polymer analysis. Features of the technique discussed include its application to the determination of absolute molar masses, high mass range, mass resolution, high sensitivity, and relative ease of operation, even for polar molecules. Molar mass distributions can be determined in a mass range that presents a problem for other mass measurement techniques. A detailed characterisation of the basic polymer chemistry can be obtained by end-group analysis. Recent developments such as delayed extraction to enhance the mass resolution obtainable, increase the usefulness of the technique. 107 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.685907 Item 177 Journal of Applied Polymer Science 69, No.2, 11th July 1998, p.363-9 IRREVERSIBLE EFFECTS OF HYGROTHERMAL AGEING ON DIGLYCIDYL ETHER OF BISPHENOL A/DICYANDIAMIDE EPOXY RESIN Xiao G Z; Shanahan M E R Ecole Nationale Superieure des Mines de Paris Results of FTIR, gravimetric tests and DMTA showed that water immersion at 50, 70 and 90C leads to the introduction of carbonyl groups in the resin and chain scission of the crosslinked structure. These irreversible structural changes induce the addition of water to the polymer initially and weight loss of the material eventually. They also lead to the irreversible decrease of

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the Tg of the diglycidyl ether of bisphenol A/ dicyandiamide epoxy resin. 21 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.684710 Item 178 Analytical Chemistry 70, No.12, 15th June 1998, p.341R-61R RAMAN SPECTROSCOPY Lyon L A; Keating C D; Fox A P; Baker B E; Lin He; Nicewarner S R; Mulvaney S P; Natan M J Pennsylvania,State University A review is presented of the literature on Raman spectroscopy published from the beginning of 1995 until late 1997. Topics covered include books, periodicals and reviews, instrumentation and data analysis, materials, Raman scattering at surfaces, non-linear Raman techniques, and biological applications of Raman spectroscopy. 654 refs. USA

Accession no.683586 Item 179 Analytical Chemistry 70, No.12, 15th June 1998, p.251R-78R SIZE EXCLUSION CHROMATOGRAPHY(SEC) AND RELATED SEPARATION TECHNIQUES Barth H G; Boyes B E; Jackson C DuPont Co.; Hewlett-Packard Co.; DuPont Automotive A review is presented of basic developments and selected applications of SEC and related techniques abstracted by Chemical Abstracts and Medline from 1996 to 1997. Aspects covered include theory, band broadening, calibration, round robin studies, automation/quality control, packings, mobile phases, non-size-exclusion effects, detectors, compositional heterogeneity, temp.rising elution fractionation, physicochemical studies, inverse SEC, preparative SEC, coupled columns/column switching, field-flow fractionation, and selected applications. 698 refs. USA

Accession no.683585 Item 180 Analytical Chemistry 70, No.12, 15th June 1998, p.229R-50R SURFACE ANALYSIS: X-RAY PHOTOELECTRON SPECTROSCOPY AND AUGER ELECTRON SPECTROSCOPY Turner N H; Schreifels J A US,Naval Research Laboratory; Fairfax,George Mason University A review of the literature published on the above for the period October 1995 to October 1997 is presented.

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References and Abstracts

Aspects of X-ray photoelectron spectroscopy(ESCA) covered include instrument calibration, data handling and line shape analysis, background subtraction, binding energies, valence band spectra, shake and multiplet splitting, X-ray-excited Auger electrons and Auger parameter, semiconductors, polymers, films, and instrumentation. Aspects of Auger electron spectroscopy covered included line shapes, beam interactions, background, quantitative analysis, depth profiling, instrumentation and data handling, and scanning Auger microscopy. Combined XPS-AES topics are also discussed. 483 refs. USA

Accession no.683584 Item 181 Analytical Chemistry 70, No.12, 15th June 1998, p.37R-52R COLUMN LIQUID CHROMATOGRAPHY: EQUIPMENT AND INSTRUMENTATION LaCourse W R; Dasenbrock C O Maryland,University A review is presented on basic developments in column liquid chromatography equipment and instrumentation for the period October 1995 to October 1997. Aspects covered include columns, instrumentation, elemental detectors, UV/ visible, IR and Raman detectors, luminescent detectors, chemiluminescence detectors, electrochemical detectors, reviews, mass spectrometry detectors, NMR detectors, other detection systems, and computation. 331 refs. USA

Accession no.683583 Item 182 Analytical Chemistry 70, No.12, 15th June 1998, p.1R-5R SOLID-STATE NUCLEAR MAGNETIC RESONANCE Dybowski C Delaware,University A review of the literature on solid-state NMR is presented, covering papers published from October 1995 to October 1997 on instrumentation and theory, chemical shift tensors of spins 1/2, quadrupolar nuclei, surfaces and catalysts, synthetic polymers, and whole biological solids. 100 refs. USA

Accession no.683581 Item 183 Pitture e Vernici 74, No.7, April 1998, p.9-11 Italian; English EVALUATION OF COATINGS BY ELECTROCHEMICAL IMPEDANCE MEASURE Benzaid A; Jerome M; Galland J; Celati N

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The use is described of electrochemical impedence spectroscopy to characterise the behaviour and the evolution of the performance of an organic coating applied on a metal substrate. The technique was applied to an epoxy paint, and is demonstrated to be well adapted to the evaluation of the durability of an organic coating. The importance is emphasised of the impedance diagram to understand the evolution of phenomena. 15 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.679859 Item 184 Chimica e l’industria 78, No.9, Nov.1996, p.1127-31 Italian REAL TIME CONTROL OF POLYURETHANE PRODUCTION USING NEAR-INFRARED SPECTROSCOPY Arenaccio G A; De Thomas F A; Hall J W; Monfre S L Perstorp Analytical; NIRSystems Inc. Real time process control in PU production was achieved by directly connecting a near-infrared spectrophotometer to the reactor. A Beer’s Law model was derived for the quantitative determination of isocyanate concentration in the reaction mixture, and statistical process control was used to observe trends in the polymerisation reaction. 10 refs. CANADA; EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; USA; WESTERN EUROPE

Accession no.679082 Item 185 Polymer International 45, No.4, April 1998, p.333-8 COMPARATIVE STUDY BY DSC AND FTIR TECHNIQUES OF AN UNSATURATED POLYESTER RESIN CURED AT DIFFERENT TEMPERATURES de la Caba K; Guerrero P; Mondragon I; Kenny J M Pais Vasco,Universidad; Perugia,University The polymerisation of a commercial polyester resin was investigated by DSC. The conversion profiles were obtained in the temperature range 60-80 C. The autocatalytic model satisfactorily describes the experimental data. FTIR spectroscopy measurements were also made to obtain both the styrene and polyester unsaturations conversions, which were compared to the overall conversion obtained by DSC. 31 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; SPAIN; WESTERN EUROPE

Accession no.678816 Item 186 London, 1996, pp.8. BS 2782:PT4:MTD433E(1996). METHODS OF

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TESTING PLASTICS - CHEMICAL PROPERTIES - DETERMINATION OF FREE ACID IN ACID ANHYDRIDE FOR HARDENERS AND ACCELERATORS IN EPOXIDE RESINS British Standards Inst. BS 2782:PT4:MTD433E(1996) Version AMD 9699. Renumbered to BS EN ISO 7327 on 15/11/97. Identical to ISO 7327-. Photocopies and loans of this document are not available from Rapra. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.671343 Item 187 Journal of Applied Polymer Science 67, No.6, 7th Feb.1998, p.1101-8 STUDY ON ISOTHERMAL CURE BEHAVIOR OF AN EPOXY-RICH/ANHYDRIDE SYSTEM BY DIFFERENTIAL SCANNING CALORIMETRY Won Ho Park; Jong Keun Lee Kumoh,National University of Technology Cure behaviour of a catalysed epoxy/anhydride system was investigated for the epoxy-rich formulation using DSC. The mixture was isothermally cured at different times and temperatures, and the cure behaviour of the samples analysed by the peak exothermic temperature and the extent of cure reaction from DSC thermograms. 24 refs. SOUTH KOREA

Accession no.670309 Item 188 Composites Science & Technology 57, No.8, Aug.1997, p.1129-37 STRESS CONCENTRATION PHENOMENON IN GRAPHITE/EPOXY COMPOSITES. TENSION/ COMPRESSION EFFECTS Amer M S; Schadler L S Rensselaer Polytechnic Institute Micro-Raman spectroscopy was used to investigate the stress concentration phenomenon and measure experimentally the stress concentration factor in graphite/ epoxy composites (M4013 fibres from Toray in Shell Epon 828 bisphenol A epoxy resin cured with mphenylenediamine) subjected to tensile and compressive stress. The results showed that the stress concentration in tension is different from that in compression. The radius of the zone of influence is much higher when the composite is under compressive stresses. The maximum stress concentration factor in both cases, however, was 1.5, limited by the ability of the interface to transfer shear stresses. The difference in stress concentration is attributed primarily to the difference in the interfacial behaviour of the composite under tension and compression. The results are discussed and explained from both fracture mechanics and energy viewpoints. 33 refs. (Presented at 6th Int. Conf.

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on Composite Interfaces, Microphenomena in Advanced Interfaces, Zichron Yaacov, Israel, 5th-8th May 1996). USA

Accession no.669966 Item 189 Composites Science & Technology 57, No.8, Aug.1997, p.899-911 FAILURE PHENOMENA IN TWODIMENSIONAL MULTIFIBRE MICROCOMPOSITES. II. RAMAN SPECTROSCOPIC STUDY OF THE INFLUENCE OF INTER-FIBRE SPACING ON STRESS CONCENTRATION van den Heuvel P W J; Peijs T; Young R J Eindhoven,University of Technology; UMIST; Manchester,University Raman spectroscopy was used to determine the influence of inter-fibre spacing on the stress concentration factor resulting from a fibre break in a two-dimensional (2-D) carbon/epoxy microcomposite. An approximately linear decrease in Raman peak position with strain was found. Microcomposites with an inter-fibre spacing varying from 0.8 to 19 fibre diameters were investigated by tensile and shear tests. The stress concentration factor was found to decrease from a value of 1.26 at an inter-fibre spacing of 0.8 fibre diameters to a value of 1.06 at an inter-fibre spacing of 10.4 fibre diameters. The experimentally found variation of the stress concentration factor with inter-fibre spacing was compared to some analytical models available in the literature. It was found that none of the models is able to describe the experimental data adequately. The effect of the stress concentration factor on the failure process is also discussed. At relatively small inter-fibre spacings the stress concentration factor is sufficiently high to cause further fibre failure in neighbouring fibres resulting in alignment of fibre breaks. At increasing inter-fibre spacing the decrease in stress concentration factor results in decreasing influence of the initial fibre break on the progressive fibre failure process and the failure process becomes more random. 38 refs. (Presented at 6th Int. Conf. on Composite Interfaces, Microphenomena in Advanced Interfaces, Zichron Yaacov, Israel, 5th-8th May 1996). EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; UK; WESTERN EUROPE

Accession no.669943 Item 190 Journal of Polymer Science : Polymer Physics Edition 36, No.2, 30th Jan.1998, p.303-18 DIELECTRIC SPECTROSCOPY AND CALORIMETRY DURING POSTCURING OF A LINEAR CHAIN POLYMER THERMOSET FORMED FROM A DIEPOXIDE AND CYCLOHEXYLAMINE, AND THE NATURE OF THE PRODUCTS

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References and Abstracts

Tombari E; Ferrari C; Salvetti G; Johari G P CNR; McMaster University The dielectric permittivity and loss spectra of an equimolar liquid mixture of diglycidyl ether of bisphenol-A and cyclohexylamine were studied during the liquid’s isothermal polymerisation or curing in separate experiments at different temperatures and thereafter during the postcuring, both on rate-heating and isothermally. Both dielectric spectroscopy and calorimetry were done simultaneously in real time, and in a continuous manner. The characteristics of the slow molecular dynamics of the polymer in the glass-softening region were discussed, and the implications of these studies for a recently proposed empirical procedure for determining the thermosetting to a crosslinked network structure. 38 refs.

Item 192 Trends in Polymer Science 5, No.12, Dec.1997, p.407-14 FLUORESCENCE SPECTROSCOPY OF POLYMER GELS AND SOLIDS Hsu Wen Huang; Horie K Tokyo,University

CANADA; EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

A review is presented of recent developments in the application of fluorescence spectroscopy to the study of the dynamics and intermolecular interactions of gels, polyimides and liquid crystalline polymers in the solid state. Fluorescence studies on the volume-phase transition in gels, using the external method, are described. The charge-transfer complex of aromatic polyimides and the marked changes in intermolecular interaction between mesogenic moieties of liquid crystal polymers, studied by the intrinsic method, are also reviewed. 36 refs.

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JAPAN

Accession no.662997 Item 191 Macromolecules 30, No.10, 19th May 1997, p.2883-90 PREPARATION AND SURFACE PROPERTIES OF ACRYLIC POLYMERS CONTAINING FLUORINATED MONOMERS Thomas R R; Anton D R; Graham W F; Darmon M J; Sauer B B; Stika K M; Swartzfager D G Du Pont de Nemours E.I.,& Co.Inc. A series of novel polymers wsa prepared by free radical solution polymerisation of a variety of hydrocarbon monomers with the (perfluoroalkyl)ethyl methacrylate monomer having an average of 7.7 carbons in the perfluoroalkyl group (ZONYL TM from Du Pont). Polymers prepared using two different methods of feeding the fluorinated monomer into the reaction mass are discussed. Through a judicious choice of the reaction conditions, some control of polymer architecture was exhibited. The resultant (perfluoroalkyl)ethyl methacrylatecontaining acrylic monomers were shown to be quite surface active in the solid state. The magnitude of surface activity depends on the fluorinated monomer feed method. The polymers were formulated into thin films and applied to a variety of surfaces. With levels at 1.5 wt% of fluorinated monomer, water and oil repellant surfaces were created. Water contact angles (advancing) of about 80-115 degrees and hexadecane contact angles (advancing) of about 6070C were observed routinely. In addition, it was observed that the concentration profile of fluorine in the films exhibited steep gradient normal to the surface when studied by angle-dependent ESCA and secondary ion mass spectroscopic depth profiling. Comonomers were mixtures of styrene, butyl methacrylate, butyl acrylate and hydroxypropyl acrylate. Crosslinking was by the isocyanurate dimer of hexamethylene diisocyanate. (Desmodur N3300 from Miles Inc.). 48 refs. USA

Accession no.663882

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Item 193 Trends in Polymer Science 5, No.12, Dec.1997, p.394-400 USE OF POSITRON ANNIHILATION LIFETIME(PAL) SPECTROSCOPY IN PROBING FREE VOLUME OF MULTICOMPONENT POLYMERIC SYSTEMS Simon G P Monash,University A review is presented of the literature on the use of the PAL spectroscopic technique to probe a number of classes of multicomponent polymeric systems, including thermoplastic blends, plasticised polymers and composites, which involve inclusion of a rigid phase. The ability to modify polymers in these ways leads to a diversity of their properties and markets and PAL spectroscopy is demonstrated to be an important method for probing their miscibility, interaction and phase behaviour. 43 refs. AUSTRALIA

Accession no.662995 Item 194 Journal of Applied Polymer Science 66, No.6, 7th Nov.1997, p.1183-93 PHENOL-FORMALDEHYDE RESOL RESINS STUDIED BY CARBON-13 NMR SPECTROSCOPY, GEL PERMEATION CHROMATOGRAPHY, AND DIFFERENTIAL SCANNING CALORIMETRY Holopainen T; Alvila L; Rainio J; Pakkanen T T Joensuu,University; Dynoresin Oy A series of phenol-formaldehyde resins was produced in the presence of sodium hydroxide catalyst and detailed structural and quantitative information was obtained by carbon-13 NMR spectroscopy. Particular attention was

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References and Abstracts

paid to the relative quantities of bridge structures, methylol groups and free phenol. Functionality and linearity of resins were also studied. The effects of the condensation F/P molar ratio on the structure and properties of the resins were studied by GPC and DSC in addition to carbon-13 NMR. 31 refs. FINLAND; SCANDINAVIA; WESTERN EUROPE

Accession no.658679 Item 195 Polymer 38, No.22, 1997, p.5699-702 EFFECTIVE WIDTH OF INTERFACE IN A STRESSED MODEL POLYMER COMPOSITE MEASURED BY MICRO-FTIR Lourie O; Wagner H D; Levin N Weizmann Institute of Science; Israel,Police HQ Materials Laboratory The effect of mechanical deformation on a UV-cured urethane-acrylate polymer and on a silicon carbide/ urethane-acrylate model composite was studied by microFTIR spectroscopy. This technique was used for the first time to measure the width of the interfacial zone beyond which the fibre has no influence on the matrix. the results were discussed. 14 refs. ISRAEL

Accession no.654334 Item 196 Macromolecular Symposia Vol.119, July 1997, p.79-87 CREEP RATE SPECTROSCOPY USING A LASER INTERFEROMETER AS ULTRA-HIGH RESOLUTION TECHNIQUE FOR STUDY OF RELAXATIONS Peschanskaya N N; Yakushev P N; Sinani A B; Bershtein V A Russian Academy of Sciences An original laser interferometry creep rate spectroscopy (CRS) method was developed and used as the lowfrequency and high-resolution technique for studying microplasticity and relaxations in different materials including brittle ones. New possibilities for CRS for polymers are demonstrated. 13 refs. RUSSIA

Accession no.653722 Item 197 Macromolecular Symposia Vol.119, July 1997, p.65-77 POLYMERS, ADDITIVES, SURFACTANTS AND THEIR MIXTURES: COMPUTER-BASED SEARCH WITH SPECIAL FTIR LIBRARIES Hummel D O Cologne,University

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The efficiency of selected search algorithms with specific FTIR libraries of application-defined chemical systems was assessed. This investigation was done with a PC of 850 MB/33 MHz, Windows 3.1 and the SPECTACLE program of LabControl/Cologne. The libraries contained standardised FTIR spectra of 3601 defined polymers, 530 industrial polymers and resins, 1969 additives (pigments, stabilisers, plasticisers, etc.), 1190 surfactants and 1614 monomers, pyrolysates and educts. For searches, the data density was reduced to 4/cm. 21 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.653721 Item 198 Macromolecular Symposia Vol.119, July 1997, p.25-48 UNDERSTANDING POLYMERS BY VIBRATIONAL SPECTROSCOPY: SOME RECENT ADVANCES IN THEORY AND EXPERIMENT Meier R J DSM Research A rapid scan version of two-dimensional spectroscopy is introduced and applied to study the phases of an acrylonitrile-butadiene-styrene polymer system. Some recent advances in the application of computational chemistry to the evaluation of vibrational spectra are presented. Some specific applications are discussed. 31 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.653719 Item 199 Analyst 122, No.9, Sept.1997, p.101R-15R ANALYTICAL EXTRACTION OF ADDITIVES FROM POLYMERS Vandenberg H J; Clifford A A; Bartle K D; Carroll J; Newton I; Garden L M; Dean J R; Costley C T Leeds,University; ICI; Newcastle,University of Northumbria Plastics contain many other small molecules as well as the polymer itself. These include additives to alter the polymer properties or prolong the life of the polymer, such as plasticisers, antioxidants and UV light absorbers. There may also be processing aids, residual monomers, low molecular weight oligomers and inadvertent contaminants present. It is important for the manufacturer and regulators to know the level of these materials in the polymer to ensure the product is fit for its intended purpose. Food contact plastics are regulated by maximum concentrations allowable in the plastic, which applies to residual monomers and processing aids as well as additives. There are some methods for determining

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References and Abstracts

concentrations of additives without extraction from the polymer, such as nuclear magnetic resonance spectrometry, UV spectrometry and UV desorption-mass spectrometry. However, in order to determine the levels in the polymer, it is usually necessary to extract the compounds quantitatively from the plastic before analysis. A review is presented of the available extraction techniques. 102 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.651430 Item 200 Polyurethanes Expo ’96. Conference Proceedings. Las Vegas, Nv., 20th-23rd Oct.1996, p.487-95. 43C6 NOVEL HR MOLDED FOAM SYSTEMS FOR IMPROVED DURABILITY Hiraide T; Utsumi H; Obata M; Ohkubo K; Kita M; Sakai S Mitsui Toatsu Chemicals Inc. (SPI,Polyurethane Div.) Studies were made of the durability of TDI and all-MDI based high resilience PU foams for use in moulded vehicle seats. The foams were characterised for mechanical properties, vibration characteristics, dynamic fatigue and crosslink density and by solid-state NMR, Fourier transform IR and dynamic mechanical spectroscopy. 16 refs. JAPAN; USA

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Item 202 Shawbury, Rapra Technology Ltd., 1997, pp.120. 12 ins. 15/4/97. Rapra Review Rept. No.95, vol.8, No. 11 1997, THERMAL ANALYSIS OF POLYMERS Sepe M P Dickten & Masch Mfg.Co. Edited by: Dolbey R (Rapra Technology Ltd.) Rapra Review Report No.95 A review is presented of the techniques involved in the thermal analysis of polymers. Techniques discussed include differential scanning calorimetry, differential photocalorimetry, thermogravimetric analysis, thermomechanical analysis, dynamic mechanical analysis, dielectric, thermally stimulated current/ relaxation map analysis analysis, and thermal conductivity analysis. 381 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.647258 Item 203 Analytical Chemistry 69, No.12, 15th June 1997, p.95R-121R ANALYSIS OF SYNTHETIC POLYMERS AND RUBBERS Smith P B; Pasztor A J; Mckelvy M L; Meunier D M; Froelicher S W; Wang F C Y Dow Chemical USA

Item 201 Trends in Polymer Science 5, No.8, Aug.1997, p.258-62 HIGH OSMOTIC PRESSURE CHROMATOGRAPHY FOR POLYMER SEPARATION Teraoka I; Luo M Brooklyn,Polytechnic University

A review is presented on the characterisation techniques for rubbers, synthetic polymers, copolymers and blends. Gas chromatography, inverse gas chromatography, pyrolysis gas chromatography, and liquid chromatography including size exclusion chromatography are included. Also covered are references to mass spectrometry, NMR, IR spectroscopy, Raman spectroscopy, and TGA and DSC. 672 refs.

High osmotic pressure chromatography (HOPC) is a technique for preparative- and processing-scale separation of polymer by molecular weight. It is applicable to any polymer that is soluble at high concentrations. In HOPC, a highly concentrated solution is injected into a column packed with porous materials of uniform pore size until the solution fills the column. Segregation of polymer by molecular weight between stationary and mobile phases is repeated at every plate, thereby enriching the front end of the transported solution with components of the highest molecular weight. Later fractions see a decrease in the molecular weight and a broadening in their distribution. HOPC has sufficiently high resolution to separate commercially available narrow-distribution standards. 25 refs.

USA

USA

USA

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Accession no.640311 Item 204 Analytical Chemistry 69, No.12, 15th June 1997, p.15R-28R COATINGS Anderson D G Witco Corp. A review is presented of analytical techniques applicable to the examination of coatings, raw materials and substrates since 1995. The most highly referenced areas were found to be IR spectroscopy, NMR, HPLC, thermal analysis and gas chromatography. 704 refs.

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Item 205 Macromolecules 30, No.6, 24th March 1997, p.1845-6 IMIDISATION STUDY BY CHARGE TRANSFER FLUORESCENCE Jae-Woong Yu; Chong Sook Paik Sung Connecticut,University Polyamic acids were prepared by reactions of 1,2,4,5benzenetetracarboxylic acid with 4,4'-diaminodiphenyl ether and 3,3',4,4'-benzophenone tetracarboxylic dianhydride with either 4,4'-diaminodiphenyl ether or 1,4phenylenediamine. Films were cast and subjected to stepwise imidisation. The extent of imidisation was determined by FTIR. Fluorescence excitation spectra were studied. Excitation at 340-380 nm resulted in emission spectra in the range 460-530 nm, but there was no oneto-one correlation between charge transfer fluorescence emission intensity and extent of imidisation. Excitation at 490 nm resulted in emission at 650-660 nm. This longer wavelength charge transfer fluorescence excitation spectrum showed a steady bathochromic shift and decrease in intensity with increasing imidisation. 12 refs. USA

Accession no.639309 Item 206 Polymer 38, No.13, 1997, p.3307-14 CASTOR OIL-BASED POLYURETHANES: 2. TRIDIMENSIONAL POLYADDITION IN BULK BETWEEN CASTOR OIL AND DIISOCYANATES - GELATION AND DETERMINATION OF WEIGHT-AVERAGE HYDROXYL FUNCTIONALITY Ngoc Buu Tran; Quang Tho Pham Vietnam,Centre de Service d’Analyse et d’Experimentation; CNRS In the bulk tridimensional polyadditions of pure triricinoleate of glycerol and castor oil with 4,4'methylenediphenylisocyanate, 2,6-tolylene diisocyanate and 1,6-hexamethylene diisocyanate, the conversions of alcohol and of isocyanate groups were found to be limited by the crosslink density of the networks. The conversion limits were independent of the natures of the diisocyanates incorporated. Critical times at the sol-gel transitions were localised by dynamic mechanical experiments. The conversion limits of OH groups in dense gels were only slightly larger than those found at critical times. The optimal conditions needed for the graphical determinations of the triricinoleate of glycerol and castor oil weight-average hydroxyl functionality were established, taking into account the variation of critical conversion values of the gels determined by quantitative carbon 13 NMR against NCO/OH ratios. The results were checked by solvent swelling experiments. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; VIETNAM; WESTERN EUROPE

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Item 207 Journal of Adhesion Science and Technology 11, No.6, 1997, p.783-95 CHANGES IN THE ADHESION STRENGTH BETWEEN COPPER THIN FILMS AND POLYIMIDE SUBSTRATES AFTER HEAT TREATMENT Iwamori S; Miyashita T; Shin F; Nozaki S; Sudoh K; Fukuda N Mitsui Toatsu Chemicals Inc. The adhesion strength between a copper thin film and a polyimide (Kapton V) (pyromellitic dianhydrideoxydianiline (PMDA-ODA)) substrate is reduced by heat treatment at 150 degrees C. In this work the changes in the adhesion strength were studied using AES, attenuated total reflection FTIR, and XPS. Analysis showed that the weak boundary layer shifted towards the Cu interface as the heat treatment time was increased. This was confirmed by examining two other polyimide substrates: biphenyl dianhydride-p-phenylene diamine (BPDA-PDA) (UpilexS) and the biphenyl dianhydride-oxydianiline (BPDAODA) (Upilex-R). Differences between the adhesion strength of the three laminate types are discussed in relation to the chemical bonding states. 15 refs. JAPAN

Accession no.638470 Item 208 Antec 97. Volume II. Conference proceedings. Toronto, 27th April-2nd May 1997, p.2451-3. 012 NEAR INFRARED CURE MONITORING AND CONTROL OF RESIN TRANSFER MOULDED EPOXY COMPOSITE USING EVANESCENT WAVE HIGH INDEX FIBRE OPTIC SENSOR Dunkers J P; Flynn K M; Huang M T US,National Inst.of Standards & Technology (SPE) Fibre optic near IR spectroscopy is used to monitor the cure of a resin transfer moulded glass fibre reinforced epoxy composite. A mini-bundle of high index optical fibres is placed in the centre of the reinforcement thickness. Spectra are collected using evanescent wave Fourier transform near infrared spectroscopy as the composite is curing. Peaks representing amine consumption are identified as good candidates for realtime monitoring and control of the epoxy cure. A cure control algorithm based on model assisted feedback control is presented. 11 refs. USA

Accession no.638411 Item 209 Polymer 38, No.10, 1997. p.2467-73 CASTOR OIL-BASED POLYURETHANES: 1. STRUCTURAL CHARACTERIZATION OF

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References and Abstracts

CASTOR OIL - NATURE OF INTACT GLYCERIDES AND DISTRIBUTION OF HYDROXYL GROUPS Ngoc Buu Tran; Vialle J; Quang Tho Pham Vietnam,Centre de Service d’Analyse et d’Experimentation; Service Central d’Analyse NMR spectroscopy was used to study the structure of castor oil. Semi-preparative liquid chromatography combined with fatty acid methyl ester gas chromatography enabled the three acyls of each intact triacyl glycerol fraction to be identified and their molecular weight was determined by mass spectrometry. From these results, the weight-average hydroxyl functionality and the hydroxyl polydispersity index could be calculated. These parameters are essential for the study of three-dimensional polycondensation of castor oil with diisocyanates to form polyurethanes. 12 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; VIETNAM; WESTERN EUROPE

Accession no.634497 Item 210 Polymer Composites 18, No.1, Feb.1997, p.133-50 CURE MONITORING OF THE LIQUID COMPOSITE MOULDING PROCESS USING FIBRE OPTIC SENSORS Woerdeman D L; Spoerre J K; Flynn K M; Parnas R S Johns Hopkins University; Southern Illinois,University; US,National Inst.of Standards & Technology Cure monitoring during liquid composite moulding of unidirectional glass fabric/epoxy resin composites was carried out by evanescent wave fluorescence measurement using a fibre optic sensor embedded in the fibre preform. The fluorescence wavelength shift during cure was correlated with monomer conversion as determined by IR spectroscopy. Glass fabrics with 40-60% volume fractions were injected with resin at a variety of driving pressures and cured at several temperatures. Several composite parts were fabricated to test the effects of vacuum pressure, injection rate, curing temperature and fibre fraction on the performance of the sensor, and the sensitivity of the sensor to the condition of the resin system was also examined. 45 refs. USA

Accession no.632375 Item 211 Applied Spectroscopy 51, No.2, Feb.1997, p.247-52 PRECISE DETERMINATION OF PERCENT CURE OF EPOXIDE POLYMERS AND COMPOSITES VIA FIBRE-OPTIC RAMAN SPECTROSCOPY AND MULTIVARIATE ANALYSIS Aust J F; Booksh K S; Stellman C M; Parnas R S; Myrick M L

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South Carolina,University; US,National Inst.of Standards & Technology A method for real time determination of the percent cure of epoxy resins via in-situ fibre optic Raman spectroscopy was developed. This method uses a probe design developed for real time monitoring of polymer curing and multivariate analysis to interpret the data and determine percent cure. The method was demonstrated in curing of laboratory samples. A preliminary study measuring cure percentage in an industrial, glass-reinforced composite was shown to be reliable in the 40-90 % cure range. 22 refs. USA

Accession no.632123 Item 212 Analytical Chemistry 69, No.7, 1st April 1997, p.229A-34A CHARCTERIZING POLYMER BY MOLECULAR PROBE CHROMATOGRAPHY(MPC) Parcher J F; Edwards R R; Yun K S Mississippi,University The principles and applications of MPC are described and it is shown that, using commercially-available instrumentation, useful information on the physical and chemical properties of polymers can be obtained. Data analysis schemes are discussed. The use of MPC for studies of glass, liquid crystal and melting transition temps., crystallinity and crystallisation kinetics, diffusion coefficients of probe solutes in molten polymers, and Flory interaction parameters is reported. 33 refs. USA

Accession no.631641 Item 213 London, Academic Press Ltd, volume 2. 23cms. 2/5/97. 96 THERMAL CHARACTERIZATION OF POLYMERIC MATERIALS. VOLUME 2. SECOND EDITION Brooklyn,Polytechnic University Edited by: Turi E A The second edition of this work provides an in-depth overview of thermal analysis. The two volume set focuses on instrumentation, applications of polymer research, development, production, quality control and technical service. Volume 2 focuses on thermosets, fibres, films, thermal characterisation of composites and thermal analysis of additives in polymers. Accession no.631438 Item 214 London, Academic Press Ltd., volume 1. 23cms. 2/5/ 97. 96 THERMAL CHARACTERIZATION OF

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POLYMERIC MATERIALS. VOLUME 1. SECOND EDITION Brooklyn,Polytechnic University Edited by: Turi E A The second edition of this work provides an in-depth overview of thermal analysis. The two volume set focuses on instrumentation, applications of polymer research, development, production, quality control and technical service. Volume 1 examines thermoanalytical instrumentation, the basis of thermal analysis, thermoplastic polymers, polymer blends and block copolymers, and elastomers. Accession no.631437 Item 215 Polymer 38, No.6, 1997, p.1291-6 INVESTIGATION OF MODIFIED PHENOLIC HARDENERS AND CURING OF AN EPOXY RESIN BY TG-FTI.R. Boeschel D; Fedtke M; Geyer W Institut fuer Technische und Makromol.Chemie; UFZ Umweltforschungszentrum Leipzig-Halle GmbH A combined thermogravimetry-FTIR spectroscopy technique was used to analyse the gases evolved during the decomposition of 2,6-dimethylol-p-cresol (DMPC) and the hexahydrophthalic acid anhydride modified hardener (HHPA-DMPC). The degradation mechanisms were discussed. Water was shown to be responsible for the bubble formation during the curing of an epoxy resin with HHPADMPC or HHPA-phenol-novolac as hardeners. 13 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; GERMANY; WESTERN EUROPE

Accession no.630789 Item 216 Polymer 38, No.5, March 1997, p.1017-20 DSC KINETIC STUDY ON THE EFFECT OF FILLER CONCENTRATION ON CROSSLINKING OF DIGLYCIDYL ETHER OF BISPHENOL-A WITH 4,4'DIAMINODIPHENYLMETHANE de Miranda M I G; Tomedi C; Bica C I D; Samiros D Rio Grande do Sul,Universidade Federal The kinetics of formation of epoxy resin composites was studied using an epoxy matrix of glycidyl ether of bisphenolA and 4,4'-diaminodiphenylmethane as curing agent in the presence of quartz flour as filler. The curing reactions of these systems were kinetically followed by DSC at different scanning rates. The activation energies of the curing reactions were obtained by non-isothermal methods: the single scanning rate of Barrett as well as the multiple scanning rate methods of Kissinger, Osawa and half-width. 18 refs. BRAZIL

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Item 217 Journal of Materials Science Letters 16, No.4, 15th Feb.1997, p.273-5 USE OF MODULATED DIFFERENTIAL SCANNING CALORIMETRY TO OBSERVE VITRIFICATION DURING EPOXY RESIN CURE Maistros G; Fontana Q P V; Attwood D; Hudd J S Cranfield,University; British Aerospace Ltd. Modulated differential scanning calorimetry (MDSC) was applied to the cure of a thermosetting epoxy resin to identify the vitrification point of the resin for a particular cure cycle. MDSC can separate thermal events that occur over the same temperature range, such as separating changes in the enthalpy of the sample from changes in the specific heat capacity. 5 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.625490 Item 218 Polymer 38, No.4, Feb.1997, p.751-7 CROSS POLARIZATION/MAGIC ANGLE SPINNING CARBON 13 N.M.R. STUDY OF CROSSLINKED POLYESTERS Grobelny J Polish Academy of Sciences Unsaturated polyesters derived from maleic anhydride and 2,2-di(4-hydroxypropoxyphenyl)propane were prepared and were then copolymerised with styrene to produce crosslinked materials. Cross-polarisation magic angle spinning carbon 13 NMR spectroscopy was used to study the unsaturated polyesters before and after copolymerisation with styrene. A correlation was found between the reaction conditions of the unsaturated polyesters with styrene and the structure of the resulting crosslinked material. Both the temperature and the amount of styrene used affected the proton relaxation times. The differences in relaxation behaviour were discussed with reference to variations in the structure and molecular mobility of the three-dimensional network. An attempt was made to separate the crosslinking effect from the copolymer effect. 22 refs. EASTERN EUROPE; POLAND

Accession no.623508 Item 219 Progress in Organic Coatings 29, Nos.1-4, Sept.-Dec.1996, p.45-53 NOVEL APPROACHES TO CHARACTERIZATION OF MELAMINE COATING RESINS Chang T T Cytec Industries Inc. Melamine coating resins are complex mixtures of melamine moieties with different degrees of

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References and Abstracts

hydroxymethylation and alkoxymethylation and their structures are traditionally identified by a general formula indicating the mole ratios of formaldehyde and alkyl groups to melamine. This expression is shown to be insufficient to reflect the complex nature of melamine resins. Following the development of efficient separation procedures, liquid chromatography/mass spectrometry was used for identification of separated components. Over thirty components were identified from analyses of methoxymethylmelamine resins and the structures of all functionalities of the separated components were determined. 10 refs. (21st International Conference in Organic Coatings Science and Technology, Athens, Greece, July 1995) USA

Accession no.623005 Item 220 Revista de Plasticos Modernos 69, No.468, June 1995, p.550-4 Spanish NEW ANALYTICAL TECHNIQUES FOR POLYMERS. II. X-RAY FLUORESCENCE (XRF) Bruna J M Izasa SA The use of X-ray fluorescence spectroscopy in the elemental analysis of polymers is discussed. Applications in the detection of key elements in PE, PP and PVC and of chlorine in epoxy resins are described. (Part I: Ibid., 69, No.467, May 1995, p.448-51).

Item 222 Journal of Materials Science Letters 15, No.21, 1st Nov.1996, p.1908-11 ANALYSIS OF STRESS CONCENTRATIONS IN MULTI-FIBRE MICROCOMPOSITES BY MEANS OF RAMAN SPECTROSCOPY Van Den Heuvel P W J; Peijs T; Young R J Eindhoven,University of Technology; UMIST; Manchester,University Preliminary results are presented showing that Raman spectroscopy makes it possible to measure stress concentration factors in fibres adjacent to a fibre break. Use is made of a carbon/epoxy resin multi-fibre microcomposite, in which five different carbon fibres are aligned parallel in a planar array at a predefined inter-fibre spacing in a dumbbell-shaped tensile bar. 16 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; UK; WESTERN EUROPE

Accession no.615176 Item 223 Composites 27A, No.10, 1996, p.973-80 INTERFACIAL MICROMECHANICS IN THERMOPLASTIC AND THERMOSETTING MATRIX CARBON FIBRE COMPOSITES Huang Y; Young R J Manchester,University

Two alternative methods of Raman imaging via global illumination and via point illumination in combination with confocal light collection were applied to the study of heterogeneous polymer systems. The spectral and spatial resolving power of the different techniques was estimated experimentally. The influence of the depth resolution on the Raman image of a defined sample structure was demonstrated in a mathematical simulation. Data are given for PE, PS, polyacrylate, and epoxy resins. 23 refs.

An experimental investigation is made of the interfacial micromechanics of carbon fibres in PMMA and polycarbonate (PC) matrices by using Raman spectroscopy to determine the distribution of interfacial shear stress along the fibre length. The effect of thermal stresses is studied by fabricating the test specimens at room temperature and subsequently annealing them under controlled conditions. Variations of fibre strain along the length of the fibre are almost linear and can be modelled by the Kelly-Tyson theory, indicating that stress transfer from matrix to fibre is primarily by frictional shear. Comparison with the same fibres in a cold-cured epoxy matrix shows that the maximum values of interfacial shear strength are much lower in the PMMA and PC models. This is due to the lack of chemical bonding in the thermoplastic systems. In the absence of residual thermal stresses the degree of interfacial adhesion in the carbon fibre composites is of the order epoxy greater than PC greater than PMMA. An increase in annealing temperature leads to an increase in interfacial shear strength. It is demonstrated for the PMMA system that this improvement is associated with the presence of radial compressive stresses induced during cooling from the annealing temperature. 26 refs.

EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; NETHERLANDS; WESTERN EUROPE

EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

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Accession no.616877 Item 221 Applied Spectroscopy 49, No. 10, Oct.1995, p.1411-30 RAMAN IMAGING OF HETEROGENEOUS POLYMERS: A COMPARISON OF GLOBAL VERSUS POINT ILLUMINATION Markwort L; Kip B; Da Silva E; Roussel B DSM; Dilor SA

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Item 224 High Performance Polymers 8, No.3, Sept.1996, p.407-26 RHEOLOGICAL AND SPECTROSCOPIC CHARACTERISATION OF THE PROPERTIES OF A PREPOLYMER FOR HIGHTEMPERATURE APPLICATIONS: THE IP960 SYSTEM Habas J P; Grenier-Loustalot M F; Peyrelasse J Pau,Universite The nadimide IP960, which was soluble in the diglyme unit until the imide oligomer stage, was characterised. High-performance liquid chromatography and proton NMR analyses of the prepolymer demonstrated its polymolecularity. Several isomer forms, due to possible conformations of the nadimide endcaps, were present in equal amounts in the medium. The combined use of DSC and rheological techniques permitted study of and explanation for the evolution of properties of the prepolymer with temp. Using FTIR spectroscopy, the structure of the polymer network was studied. The results appeared to confirm the validity of the crosslinking diagram of nadic structures proposed by Wong et al. Thermomechanical analysis of the crosslinked compound showed that the Tg of the polymer was close to 292C. It also revealed, on the curve of the modulus, the presence of two peaks (gamma and beta), associated with secondary mechanical relaxations within macromolecular chains. 25 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.607028 Item 225 Macromolecular Chemistry & Physics 197, No.9, Sept.1996, p.3001-15 THERMOSETS OBTAINED BY CHEMICAL MODIFICATION OF POLYEPICHLOROHYDRIN WITH VINYL-TERMINATED AROMATIC CARBOXYLATES Reina J A; Serra A; Cadiz V Tarragona,Universitat Rovira i Virgili Polyepichlorohydrin was modified with several vinylterminated aromatic potassium carboxylates under solidliquid phase-transfer conditions. Characterisation was undertaken by NMR, FTIR, elemental analysis, viscosimetry, size exclusion chromatography, DSC, and TGA. Arrhenius kinetic parameters were determined for dicumyl peroxide initiated crosslinking by calorimetry. 14 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; SPAIN; WESTERN EUROPE

Accession no.606869 Item 226 Journal of Polymer Science : Polymer Physics Edition 32, No.15, 30th Nov.1994, p.2519-27

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IMPEDANCE SPECTROSCOPY OF REACTIVE POLYMERS. 1 Bellucci F; Valentino M; Monetta T; Nicodemo L; Kenny J; Nicolais L; Mijovic J Napoli,Universita; Brooklyn,Polytechnic University Dielectric measurements were used to study the curing reaction in an epoxy/amine formulation. The authors showed how the values of complex impedence measured during cure could be used to calculate ionic resistivity which, in turn, could be used to evaluate the degree of cure. The values of normalised degree of cure calculated from dielectric and calorimetric measurements were in good agreement. 28 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; USA; WESTERN EUROPE

Accession no.604874 Item 227 Journal of Polymer Science : Polymer Physics Edition 32, No.14, 15th Nov.1994, p.2421-33 ATR ANALYSIS OF THE OIL-ABSORPTION ABILITY OF A TWO-PART EPOXY ADHESIVE ON OIL-CONTAMINATED METAL SUBSTRATES Hong S G; Shu H X Yuan Ze,Institute of Technology The oil absorption behaviour of a room temperature cured, two-part epoxy adhesive on cold rolled steel, 2024aluminium and electrogalvanised steel substrates was studied by means of attenuated total reflection infrared spectroscopy. Results showed that as much as a 20 micron thickness of oil could be absorbed from the cold rolled steel and aluminium substrates, but much less from the electrogalvanised steel. However, heat applied during cure greatly increased the absorption of oil from this last substrate. More oil-compatible amide-containing molecules were present in the adhesive resin near the oiled metal surfaces than further away. The oil absorption behaviour was thought to result from the different amounts of curing agents adsorbed on the metal surfaces. The preferential adsorption of curing agents on to the electrogalvanised steel surfaces resulted in an oilincompatible, epoxy-rich layer near the adhesive/substrate interface, which blocked oil absorption. The oil did not appear to inhibit the cure of the adhesive. 39 refs. TAIWAN

Accession no.604823 Item 228 Composites Part A: Applied Science and Manufacturing 27A, No.9, 1996, p.799-804 STUDY OF THE INTERACTION OF CARBON FIBRE SURFACE WITH A MONOFUNCTIONAL EPOXY RESIN Atkinson K E; Farrow G J; Jones C

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References and Abstracts

Liverpool,University X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SIMS) are used to determine the chemical changes observed as a result of interactions between carbon fibre surfaces and epoxy resins. A comparison is made between untreated, commercially treated and air plasma treated carbon fibres. Both positive and negative static SIMS results indicate the presence of nitrogen and oxygen containing fragments as a result of air plasma treatment, the spectra from commercially treated fibres are dominated by contaminants. Fibres are then sized in the monofunctional epoxy resin, 1,2 epoxy-3-phenoxypropane, and further analysis carried out to determine the chemical nature of the fibre resin interface. Angle resolved XPS is used to confirm the presence of a layer of resin. Positive ion fragments from static SIMS data are identified as species which have been formed as a result of the epoxy molecule chemically reacting with species on the fibre surface. Surface energy measurements are recorded and it is shown that the polar component of surface energy is greatly increased as a result of surface treatment. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.603038 Item 229 Applied Spectroscopy 50, No.7, July 1996, p.900-5 IN SITU NEAR-IR CURE MONITORING OF A MODEL EPOXY MATRIX COMPOSITE Cossins S; Connell M; Cross B; Winter R; Kellar J South Dakota,School of Mines & Technology The curing of an epoxy resin adjacent to an embedded silica optical fibre was monitored in situ by evanescent wave spectroscopy. The epoxy resin was partially fluorinated and had a lower refractive index than the silica fibre. The lower refractive index of the epoxy resin allowed the silica optical fibre to be used as a waveguide for the internal reflection of the near-IR light. The epoxy resin curing was determined as a function of time and temp. by analysis of the near-IR spectrum from the epoxy adjacent to the fibre obtained by the interaction of the evanescent wave that occurred at each internal reflection with the low refractive index epoxy resin. The results obtained showed that epoxy ring-opening and crosslinking reactions could be followed in real time. Treatment of the fibre with a silane coupling agent had no observable effect on the curing reaction of the epoxy resin. 27 refs. USA

Accession no.600870 Item 230 Journal of Cellular Plastics 32, No.2, March/April 1996, p.159-71 DETERMINATION OF THE BLOWING AGENT

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DISTRIBUTION IN RIGID POLYURETHANE FOAM Svanstrom M; Ramnas O Chalmers University of Technology The amount and distribution of blowing agent in rigid PU foam were determined by several methods. A method involving solvent extraction with subsequent gas chromatographic analysis was developed and found to be advantageous for CFC-blown foam, together with a combustion method in which the chloride ions formed were determined by titration. The solvent extraction method was also successfully applied to blowing agents in CFC-free foams. Three methods involving heating and weight loss determination were evaluated. They were easy to use, but corrections for thermal decomposition of the polymer were required. About half the total amount of CFC-11 in the studied PU foams from district heating pipes was found to be dissolved in the polymer matrix. 15 refs. SCANDINAVIA; SWEDEN; WESTERN EUROPE

Accession no.600790 Item 231 Journal of Applied Polymer Science 61, No.5, 1st Aug.1996, p.775-82 EFFECT OF MOISTURE CONTENT ON THE ISOCYANATE/WOOD ADHESIVE BONDLINE BY NITROGEN-15 CROSS-POLARISATION/ MAGIC ANGLE SPINNING(CP/MAS) NMR Wendler S L; Frazier C E Virginia,Polytechnic Institute & State University A 99% nitrogen-15-labelled polymeric diphenylmethane diisocyanate(pMDI) resin was used to prepare a series of wood/nitrogen-15-pMDI composites at various wood precure moisture contents. Cure chemistry and bondline morphology were monitored using nitrogen-15 CP/MAS NMR. Biuret-type structures were identified as the predominant chemical moieties when dry wood flakes were bonded together, while urea linkages were predominant at higher precure moisture. Urea and urethane signal overlap made the unambiguous identification of urethane difficult. Relaxation studies using variable contact times were complicated by excessively long CP rates for non-protonated nitrogens. Experiments using variable spin lock periods prior to a fixed contact time indicated that the cured resin in these composites was homogeneous. 29 refs. USA

Accession no.598660 Item 232 Analyst 121, No.6, June 1996, p.53R-63R SILICONES AND THEIR DETERMINATION IN BIOLOGICAL MATRICES: A REVIEW Cavic-Vlasak B A; Thompson M; Smith D C

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Toronto,University A review of the literature on silicones and their determination in biological matrices is presented. The following topics are covered: properties and applications of silicones; biochemistry of elemental silicon and silicones; general approach to the determination of trace amounts of silicones in biological materials; survey of methods used for non-specific and silicon-specific microstructural determination of silicones in tissues (microanalysis); silicone-specific (elemental) techniques for the detection of silicones in biological materials; survey of silicone-specific techniques (IR, FTIR, Raman, NMR spectroscopies, gas chromatography(GC) and GCmass spectrometry methods); and problem of speciation of silicon and identification of silicone biotransformation products in biological samples. 124 refs. CANADA

Accession no.595316 Item 233 Characterization of Solid Polymers. New Techniques and Developments. London,Chapman & Hall, 1994, p.122-65. 91T NEUTRON-SCATTERING TECHNIQUES Rennie A R Cambridge,University Edited by: Spells S J (Sheffield,Hallam University) A brief introduction is provided to the theory of neutron scattering. It is limited to a discussion of the principles and sufficient introduction to the terminology to provide a guide through the literature. Emphasis is placed on the distinctive features and recent developments in the application of neutrons to studies of solid polymers. Neutrons are often used as just one of several different experimental tools to investigate a given problem in polymer science. After a description of the instrumentation, the main categories of neutron experiment are considered in turn and recent, significant work is highlighted. 269 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

where the results are only qualitative and usually yield a variety of degradation products. 13 refs. AUSTRALIA

Accession no.589815 Item 235 Advances in Polymer Science Vol.125, 1996, p.147-86 ULTRASONIC SPECTROSCOPY FOR POLYMERIC MATERIALS Matsushige K; Hiramatsu N; Okabe H Kyoto,University; Fukuoka,University; Kyushu,University The principle of an ultrasonic spectroscopy technique which utilises a wide-band polymeric transducer and the fast Fourier transformation analysis of a single pulse is introduced and its application to various polymeric materials is reviewed. Ultrasonic analysis of mechanical relaxation processes and phase transitions in solid polymers is described, together with practical nondestructive inspection of defects in composite materials. 24 refs. JAPAN

Accession no.589078 Item 236 Polyurethanes ’95. Conference Proceedings. Chicago, Il., 26th-29th Sept.1995, p.34-8. 43C6 METHOD FOR THE DETERMINATION OF CELL GAS CONTENT IN POLYURETHANE FOAMS Bogdan M C; Orlowski D F; Bennington J L; Welch J L AlliedSignal Inc. (SPI,Polyurethane Div.) A gas chromatographic technique is described for determining the composition of cell gases in PU foams. The method is shown to be applicable to foams produced with the full range of blowing agents. USA

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Accession no.594614 Item 234 Urethanes Technology 13, No.2, April/May 1996, p.22-4 DEVELOPMENTS IN PU ANALYSIS: SAMPLESIZE REQUIREMENTS SHRINK Haken J K New South Wales,University

Item 237 Polymer 37, No.7, March 1996, p.1065-9 SOLID-STATE NMR DETERMINATION OF RESIDUAL UNSATURATION IN STYRENECURED POLYESTER RESINS Newman R H; Patterson K H Industrial Research Ltd.

It is demonstrated that the fusion analysis of polyurethanes can be conducted using very small samples, comparable in size to those required for pyrolysis gas chromatography. The results obtained are essentially quantitative and are claimed to be superior to those resulting from pyrolysis

A resin containing fumarate, isophthalate and propylene glycol structural units was cured with styrene and characterised by carbon-13 solid state NMR. The degree of residual polyester unsaturation was estimated from relative areas of peaks at 172 ppm (carboxylic carbon in

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References and Abstracts

unreacted fumarate structural units). Decreasing the styrene content below 47% by weight resulted in residual polyester unsaturation. Results were interpreted in terms of a statistical model for copolymerisation, providing evidence for low reactivity of fumarate structural units relative to diethyl fumarate and drawing attention to differences in reactivity between the resin system used in the present work and those used in earlier studies. Comparison between results presented here and in other papers draw attention to differences in the minimum styrene content required to suppress residual unsaturation or undercuring in different resin/initiator/promoter systems. 13 refs. NEW ZEALAND

Accession no.588649 Item 238 ICCM/9. Volume 6: Composites Properties and Applications. Conference Proceedings. Madrid, 12th-16th July 1993, p.744-51. 627 DELAMINATION DEFECTS IN CFRP COMPOSITES: HIGH FREQUENCY ULTRASONICS TO VISUALISE THE THIRD DIMENSION Wevers M; De Meester P Leuven,Catholic University Edited by: Miravete A (Zaragoza,University) A high frequency ultrasonic C-scan technique was used to study delamination defects in carbon fibre-reinforced epoxy laminates and a computer program was developed to produce quasi-3D plots of the damage from the ultrasonic reflections obtained. An X-ray radiograph was taken for each specimen to check the information obtained by the ultrasonic scanning technique. It was concluded that high frequency ultrasonics can be used with a high degree of resolution and reproducibility. 3 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; WESTERN EUROPE

Accession no.588211 Item 239 Macromolecules 29, No.7, 25th March 1996, p.2555-62 SPECTROSCOPIC CHARACTERISATION OF HYDROGEN BONDING IN POLY(URETHANEROTAXANE)S Marand E; Qinchun Hu; Gibson H W; Veytsman B Virginia,Polytechnic Institute & State University; Pennsylvania,State University The hydrogen bonding interactions in a series of poly(urethane-rotaxane)s were studied by IR spectroscopy. Spectroscopic data, together with a onedimensional mean-field model, were used to calculate the enthalpy of hydrogen bond formation involving a PU NH moiety and an ether oxygen atom located in a macrocycle threaded along the PU backbone. The average

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enthalpy of hydrogen bonding was estimated at 3.0 kcal/ mol. 26 refs. USA

Accession no.587498 Item 240 3rd International Conference on Deformation and Fracture of Composites. Conference Proceedings. Guildford, 27th-29th March 1995, p.105-14. 627;951 EFFECT OF THERMAL STRESSES ON THE INTERFACIAL MICROMECHANICS OF MODEL CARBON FIBRE COMPOSITES Huang Y; Young R J Manchester,Materials Science Centre (Institute of Materials) The interfacial shear strength of carbon fibre-reinforced epoxy resin composites cured either at room temperature or at 80C was evaluated by the fragmentation test and Raman spectroscopy. Both techniques showed that the composite cured at high temperature had a significantly higher interfacial shear strength. This increase could be explained by the existence of a radial pressure at the interface resulting from thermal expansion coefficient mismatch between the fibre and the matrix during cooling from the curing temperature. Raman spectroscopy was also used to determine the axial compressive strain in the fibres after high temperature curing. It was also observed that the level of debonding during fragmentation in the hot cured composite was greatly reduced at a given strain level. 30 refs. UMIST; MANCHESTER,UNIVERSITY EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.586727 Item 241 Advanced Composites Letters 4, No.6, 1995, p.189-93 USE OF LOW RESOLUTION NMR TO MONITOR THE EXTENT OF CURE IN AN EPOXY RESIN SYSTEM Newbury A L; Lowry R B; Short D Plymouth,University Solidification of samples of an epoxy resin was monitored by low field NMR. The shape of the free induction decay curve and the initial signal intensity are shown to depend upon the state of cure and results from this method are compared with those from mechanical measurements. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.586025 Item 242 Industrial & Engineering Chemistry Research 35, No.3, March 1996, p.963-72

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IN-SITU NEAR-INFRARED SPECTROSCOPIC INVESTIGATION OF THE KINETICS AND MECHANISMS OF REACTIONS BETWEEN PHENYL GLYCIDYL ETHER (PGE) AND MULTIFUNCTIONAL AROMATIC AMINES Lisheng Xu; Fu J H; Schlup J R Kansas State University Two model systems for epoxy-amine reactions, phenyl glycidyl ether with aniline and with m-phenylenediamine, were studied via in-situ near-IR spectroscopy. The quality of the near-IR spectra enabled concentrations of individual chemical species to be obtained in real time. A mechanistic model was proposed, and the corresponding kinetic parameters were evaluated. 27 refs. USA

Accession no.586022 Item 243 Polymer 37, No.5, 1996, p.721-7 HIGH-TEMPERATURE NMR TECHNIQUES FOR STUDYING CROSSLINKED EPOXY SYSTEMS Harris R K; Yeung R R; Johncock P; Jones D A Durham,University; UK,Defence Research Agency The network structures formed when the diglycidyl ether of bisphenol A is cured with two stoichiometries of diaminodiphenyl sulphone were studied by solid-state carbon-13 NMR at temperatures well above the Tg. Highresolution spectra were obtained giving detailed information on the chemistry of these structures. Spectral editing and two-dimensional techniques more usually associated with solution-state NMR were used to confirm structural elements previously postulated. The value of high-temperature NMR for amorphous and rigid systems such as epoxy resins is discussed. 13 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.585652 Item 244 Euradh ’94. Conference Proceedings. Mulhouse, 12th-15th Sept.1994, p.90-4. 9(12)4 ELASTOMER/GLASS ADHESION: CHARACTERISATION OF FAILURE SURFACES BY ATOMIC FORCE MICROSCOPY AND INFRARED SPECTROSCOPY Ryschenkow G; Remy P; Touraine S CNRS (Societe Francaise du Vide; Institute of Materials; Dechema Institut) Atomic force microscopy and infrared spectroscopy were used to characterise the failure surfaces during peeling tests carried out with polydimethylsiloxane or PU films in adhesion on a flat glass surface. Different modes of rupture were observed, depending on the temperature and speed used

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during the peeling tests. The effect of ageing the adhesive assemblies in hot and wet conditions before peeling was also studied. The results were discussed. 10 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.584820 Item 245 Trends in Polymer Science 4, No.3, March 1996, p.81-6 MASS SPECTROMETRY OF SYNTHETIC POLYMERS. MERE ADVANCES OR REVOLUTION? Montaudo G Catania,University This review illustrates some of the new mass spectrometry techniques for the analysis of macromolecules, and cited pertinent references from the most recent literature. The use of mass spectrometry in structural analysis, end group detection, molecular weight determination, and determination of copolymer sequences are examined in detail. 47 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.584793 Item 246 Trends in Polymer Science 4, No.3, March 1996, p.74-81 IMPEDANCE SPECTROSCOPY OF REACTIVE POLYMERS Mijovic J; Belluci F New York,Polytechnic University Fundamental aspects of impedance spectroscopy are outlined, then its use for monitoring chemical and physical changes that accompany the processing of reactive polymers is described. Examples are given of the correlations between the measured impedance and various chemorheological phenomena that characterise cure, i.e. the conversion of liquid monomers into a threedimensional crosslinked network. 27 refs. USA

Accession no.584792 Item 247 Journal of Applied Polymer Science 59, No.13, 28th March 1996, p.2055-68 CARBON-13 NMR ANALYSIS METHOD FOR MUF AND MF RESIN STRENGTH AND FORMALDEHYDE EMISSION Panangama L A; Pizzi A Witwatersrand,University A method based on the use of carbon-13 NMR relative peak intensity ratios for chemical groups known to contribute to melamine-urea-formaldehyde (MUF) and

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References and Abstracts

melamine-formaldehyde resin (MF) strength and formaldehyde emission is presented. The method relates results obtained by carbon-13 NMR analysis of liquid MUF and MF resins with their strength and formaldehyde emission in the hardened state. 20 refs. SOUTH AFRICA

Accession no.584706 Item 248 Cellular Polymers III. Conference proceedings. Coventry, 27th-28th April 1995, paper 3. 6124 USE OF FTIR TO ANALYSE FIRE GASES FROM BURNING POLYURETHANE FOAMS Paul K T Rapra Technology Ltd. (Rapra Technology Ltd.) A large number of different techniques may be used to analyse fire gases including gas chromatography, mass spectrometry, infrared absorption, ion chromatography, chemiluminescence, specific ion electrodes as well as various colourmetric and titrametric techniques. The use of Fourier Transform Infrared Analysis (FTIR) enables a number of the more important gases to be determined continuously. These gases include those of particular importance to polyurethane foam containing fires, e.g. hydrogen cyanide, nitrogen oxides, hydrogen chloride and hydrogen bromide (from flame retardant additives) as well as carbon monoxide and carbon dioxide which are produced from all fires. The use and limitations of FTIR to analyse fire gases in general is discussed and the fire gases produced by burning polyurethane foams of different types are compared. 4 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Item 250 MRS Bulletin 21, No.1, Jan.1996, p.37-42 ION-BEAM ANALYSIS OF POLYMER SURFACES AND INTERFACES Kramer E J Cornell University A review is presented of the literature on the use of ionbeam analysis in polymers. Particular attention is paid to Rutherford backscattering spectrometry, forward recoil spectrometry, higher depth resolution forward recoil spectrometry and radiation damage. 66 refs. USA

Accession no.580086 Item 251 Elastomer Technology Handbook. Boca Raton, Fl., CRC Press, 1993, p.105-258 011 USE OF THERMAL ANALYSIS IN POLYMER CHARACTERISATION Sepe M P Dickten & Masch Mfg.Co. Edited by: Cheremisinoff N P (SciTech Technical Services) An update is presented on the collaborative efforts coordinated by Turi. Brief discussions of new techniques are included. Methods examined in detail are DSC, TGA, thermomechanical analysis, dynamic mechanical analysis, dielectric analysis, thermally stimulated current, relaxation map analysis, free volume microprobe, differential photocalorimetry, thermal conductivity analysis, and melt elasticity analysis. 226 refs. USA

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Item 249 International Polymer Science and Technology 22, No.9, 1995, p.T/48-9 ANALYSIS OF AIR DURING THE USE OF EPOXY-CYANATE LACQUER MATERIALS Zavorovskaya N A; Titova O N; Kolesnik E P

Item 252 Polymers for Advanced Technologies 7, No.1, Jan.1996, p.1-16 IN SITU REAL-TIME MONITORING OF EPOXY/ AMINE KINETICS BY REMOTE NEAR INFRARED SPECTROSCOPY Mijovic J; Andjelic S; Kenny J M Brooklyn,Polytechnic University; Perugia,University

IR spectrophotometry and gas chromatography were used to investigate the qualitative composition of volatile components of epoxy-cyanate lacquer UR-231, which is widely used in the electronics industry. The lacquer is based on an alkide-epoxy resin E-30, and the hardener is urethane DGU, which is a 70% solution in cyclohexane of the product of interaction of toluylene diisocyanate and diethylene glycol. The solvents used are a mixture of xylene, butyl acetate, and cyclohexanone. 2 refs. Translation of Plast Massy, No.2, 1994, p.75. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology. RUSSIA

Accession no.580948

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An experimental set-up for in situ real time monitoring of chemical reactions by remote fibre optic near-IR spectroscopy was developed. A series of epoxy/amine formulations, both non-polymer-forming and polymerforming, was prepared and the reaction kinetics were investigated. Accurate and reproducible spectra were generated, the characteristic near-IR peaks assigned and the reaction kinetics evaluated by monitoring the rates of disappearance and/or appearance of the characteristic peaks. The effect of the chemical structure and functionality of the components was demonstrated and a method proposed to correlate the spectral information with

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the chemophysical changes in multifunctional formulations. 28 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; USA; WESTERN EUROPE

Accession no.578262 Item 253 Journal of Polymer Science : Polymer Physics Edition 34, No.2, 30th Jan.1996, p.379-88 IMPEDANCE SPECTROSCOPY OF REACTIVE POLYMERS. III. CORRELATIONS BETWEEN DIELECTRIC, SPECTROSCOPIC AND RHEOLOGICAL PROPERTIES DURING CURE OF A TRIFUNCTIONAL EPOXY RESIN Mijovic J; Andjelic S; Fitz B; Zurawsky W; Mondragon I; Bellucci F; Nicolais L New York,Polytechnic University; Escuela Universitaria de Ingenieria Tecnica Industrial; Napoli,Universita An investigation was carried out of correlations between dielectric, vibrational spectroscopic, and rheological properties during cure of a thermoset formulation composed of trifunctional epoxy resin and tetrafunctional amine. Experimental techniques used included impedance spectroscopy, near-infrared spectroscopy, steady shear, and dynamic mechanical measurements. 17 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; SPAIN; USA; WESTERN EUROPE

Accession no.577585 Item 254 Antec ’95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2816-9. 012 UV REFLECTION SPECTROSCOPY FOR INSITU POLYMER REACTION MONITORING USING BIFURCATED OPTICAL FIBRE Paik H J; Hestermann D K; Sung N H Tufts University (SPE) The in-situ monitoring of polymer reactions by UV reflection spectroscopy using a bifurcated multi-fibre optical probe is discussed. Results are presented of studies of cure reactions in epoxy resins and polyimides. The effects of surface roughness on signal intensity due to scattering are examined by reference to studies of polyimide prepregs. 7 refs. USA

Accession no.576620 Item 255 Antec ’95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2805-11. 012 CURE MONITORING WITH AN EVANESCENT WAVE FLUORESCENCE SENSOR Woerdeman D L; Parnas R S

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Johns Hopkins University; US,National Inst.of Standards & Technology (SPE) The cure of epoxy resins in fibre-reinforced preforms was monitored by evanescent wave fluorescence sensing using a high refractive index optical fibre sensor and a zwitterion and dimethylaminonitrostilbene as fluorescent dyes. The fluorescence signal was correlated with resin cure by comparison with IR spectra collected at several temperatures. 17 refs. USA

Accession no.576618 Item 256 Journal of Applied Polymer Science 58, No.9, 28th Nov.1995, p.1491-4 EPOXY RESINS BASED ON BISPHENOL S. II. HPLC ANALYSIS Podzimek S; Sykora V; Horalek J; Svestka S SYNPO Three types of bisphenol S based epoxy resins were prepared by three methods, (a) reaction of bisphenol S with epichlorohydrin in alkaline solution, (b) reaction of a mixture of bisphenols S and A with epichlorohydrin in alkaline solution, and (c) thermal treatment of bisphenol S with the diglycidyl ether of bisphenol A. They were analysed by reversed phase HPLC. Some components present in the reaction products were identified by three methods (i) analogy with bisphenol A-based epoxies, (ii) combination of semipreparative HPLC with IR and NMR spectroscopy, (iii) derivatisation of resins with hydrochloric acid or sodium hydroxide. 13 refs. CZECH REPUBLIC

Accession no.571570 Item 257 Antec ’95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2446-51. 012 INVERSE GAS CHROMATOGRAPHY: A VERSATILE TOOL FOR POLYMER SURFACE CHARACTERISATION Schreiber H P Montreal,Ecole Polytechnique (SPE) Inverse gas chromatography (IGC) is examined as a means for the evaluation of surface energies and acidbase interaction potentials in polymers and polymer additives. A pair interaction parameter using IGC data is introduced for quantitatively expressing acid-base interactions at interfaces involving polymers. An example relates to the development of adhesion in lap shear joints consisting of PVC substrates bonded with a PU adhesive. 10 refs. CANADA; USA

Accession no.571346

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References and Abstracts

Item 258 Antec ’95. Vol.II. Conference Proceedings. Boston, Ma., 7th-11th May 1995, p.2437-41. 012 COMPOSITE INTERPHASE STUDY BY EVANESCENT FIBRE OPTIC FLUORESCENCE Fuchs A; Sung N H Tufts University (SPE) In-situ studies of curing reactions in an epoxy resin/ diaminodiphenylsulphone system at the glass fibre/resin interface were conducted by fluorescence spectroscopy with evanescent wave probing using a sapphire optic fibre. The cure reaction was followed by diaminoazobenzene as extrinsic fluorophore, and sulphorhodamine was used as the internal reference dye to normalise the fluorescence intensity for quantitative analysis. The results indicated different cure kinetics and final extent of amine cure reaction between the bulk and interphase cure regions. 16 refs. USA

Accession no.571344 Item 259 Polymer News 20, No.10, Oct.1995, p.317-20 POLYMER COMPOSITES. NOVEL RESEARCH TRENDS. II. IN SITU REAL TIME MONITORING OF REACTIVE SYSTEMS BY REMOTE FIBRE OPTIC NEAR-IR SPECTROSCOPY Mijovic J; Andjelic S Brooklyn,Polytechnic University Details are given of recent developments in sensors for reactive processes with particular emphasis given to the use of remote near-IR spectroscopy in reactive process monitoring. Results are presented from an experimental set-up using an epoxy resin/amine model system. 18 refs. USA

Accession no.569373 Item 260 Macromolecules 28, No.22, 23rd Oct.1995, p.7441-6 FOURIER TRANSFORM INFRARED ANALYSIS OF A LINEAR, ANHYDRIDE-CURED EPOXY Tadros R; Timm D C Nebraska,University A linear-chained epoxy resin was formulated from phenyl glycidyl ether and nadic methyl anhydride catalysed by benzyldimethylamine. Intermolecular polymerisations were modelled as a parallel set of propagation reactions. FTIR spectroscopy was used to determine the concentrations of the oxirane, anhydride and ester moieties within the resin as a function of time for two isothermal cures. Data analyses yielded the propagation rate constant as a function of temp. and the concentration

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of initiator, including contributions from impurities within the resin. Results obtained compared favourably with measurements on fractionated resins, using GPC. Population density distributions are described by Poisson molar distributions for this resin. 25 refs. USA

Accession no.569011 Item 261 Journal of Applied Polymer Science 58, No.10, 5th Dec.1995, p.1689-700 DIFFERENTIAL SCANNING AND DYNAMIC MECHANICAL ANALYSIS OF AMINEMODIFIED UREA-FORMALDEHYDE ADHESIVE Ebewele R O Ahmadu Bello,University The object of this study was to clarify the physical and morphological factors responsible for the improved performance with modified adhesives using DSC to determine relative cure reaction rates and dynamic mechanical analysis to determine changes in storage and loss moduli during cure. 21 refs. NIGERIA

Accession no.568015 Item 262 American Industrial Hygiene Association Journal 56, No.6, June 1995, p.581-9 CRITICAL REVIEW OF METHODS OF SAMPLING, ANALYSIS AND MONITORING FOR TDI AND MDI Levine S P; Hillig K J D; Dharmarajan V; Spence M W; Baker M D Michigan,University; BASF Corp.; Bayer Corp.; Dow Chemical Co.; ICI The review includes a ‘tutorial-style’ discussion of definitions and basic principles and procedures of quality control and metrology for sampling, analysis and monitoring of TDI and MDI. Recommendations are given for future work. Proper exposure assessment is shown to be critical in the risk analysis process, as both exposure and effect measurements are required. 49 refs. USA

Accession no.566656 Item 263 Cellular Polymers II. Conference proceedings. Edinburgh, 23-25th March 1993, paper 9. 6124 CORRELATED VIEW OF REACTION KINETICS AND STRUCTURE DEVELOPMENT DURING THE REACTIVE PROCESSING OF WATER BLOWN, FLEXIBLE POLYURETHANE FOAM Elwell M J; Ryan A J UMIST; Dow Benelux NV

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(Rapra Technology Ltd.) The formation of urethane, soluble urea and hydrogen bonded urea species during the fast bulk copolymerisation which forms flexible PU foam is studied using the adiabatic reactor method and forced-adiabatic, timeresolved FT-IR spectroscopy. The evolution of timebonded urea is analysed emphasising the onset of microphase separation of urea hard segment sequences and their subsequent growth into hydrogen bonded urea hard segment domains. FT-IR spectroscopy indicates that the microphase separation transition occurred at a critical conversion of isocyanate functional groups. The results also indicate that the microphase separation process appears to occur via a nucleation and growth mechanism. 25 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; UK; WESTERN EUROPE

Accession no.562722 Item 264 Macromolecules 28, No.16, 31st July 1995, p.5581-4 ROOM-TEMPERATURE PHOSPHORESCENCE STUDIES OF EPOXY RESIN CURED BY AN AROMATIC DIAMINE Jian Cheng Song; Chong Sook Paik Sung Connecticut,University The applicability of phosphorescence spectroscopy was investigated for cure characterisation of epoxy resin cured by an aromatic diamine. By using a time-resolved method to separate fluorescence from phosphorescence, the room temperature phosphorescence (RTP) behaviour of a commonly used curing agent, bis(p-aminophenyl) sulphone, was studied. RTP emission spectra with a maximum around 500 nm were obtained. Both RTP emission and excitation intensity increased very sharply with cure time due to the increase in the rigidity of the cured epoxy. They could be correlated to the extent of cure of epoxy, when properly calibrated. The triplet lifetime obtained by monitoring RTP emission decay at 500 nm increased from zero to about 40 ms following cure at 160C for 180 minutes. Correlation curves of the triplet lifetime with the extent of cure and the Tg were also obtained. Thus, the triplet lifetime provides a way to estimate the cure extent without the need to calibrate the RTP emission intensity. While these RTP characteristics cannot be used for in-situ cure monitoring, they can be used as a sensitive cure estimate technique in lightly cured prepregs for composites or after a cure cycle. 12 refs. USA

Accession no.562546 Item 265 London, Chapman & Hall, 1994, pp.vii, 368. LS.69. 9ins. 9/6/94. 91T CHARACTERIZATION OF SOLID POLYMERS :

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NEW TECHNIQUES AND DEVELOPMENTS Sheffield,Hallam University Edited by: Spells S J This volume reviews progress in the field of polymer characterisation. Eight chapters highlight the key analytical methods : electron crystallography; microscopy; synchrotron radiation; neutron-scattering techniques; mixed-crystal infra-red spectroscopy; raman spectroscopy; NMR spectroscopy; and polymer surface characterisation by XPS and SIMS. Currently available instrumentation is reviewed and recent developments in structural techniques are described. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.559862 Item 266 Polymers & Polymer Composites 3, No.3, 1995, p.153-63 STRUCTURE AND MOLECULAR WEIGHT DETERMINATIONS OF UNSATURATED POLYESTER PREPOLYMERS BY STERIC EXCLUSION CHROMATOGRAPHY Leroux F; Mortaigne B; Belan F Centre de Recherches et d’Etudes d’Arcueil; Cray Valley Total Four model unsaturated polyester prepolymers and two industrial resins were studied by size exclusion chromatography. A calibration curve was set up with model resins and used to characterise the industrial unsaturated polyester resins. Weight average molecular prepolymer weights were determined from the new calibration curve. They were lower than those determined with PS or epoxy resin calibration curves. The observation of SEC chromatographs proves the formation of diolisophthalic acid-diol and maleic anhydride-diol-maleic anhydride structures in the beginning of polycondensation reactions. This gives information on the future structure of the unsaturated polyester network. 26 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.559473 Item 267 Journal of Polymer Science : Polymer Physics Edition 33, No.11, Aug.1995, p.1603-20 ANALYSIS OF POLYURETHANES USING CORE EXCITATION SPECTROSCOPY. II. INNER SHELL SPECTRA OF ETHER, UREA AND CARBAMATE MODEL COMPOUNDS Urquhart S G; Hitchcock A P; Priester R D; Rightor E G McMaster University; Dow Chemical USA Core excitation spectra of selected small molecule analogue species were obtained to aid in the interpretation of the core excitation spectra of model MDI PU polymers. Oscillator strength spectra for C 1s and O 1s core

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References and Abstracts

excitation of diethyl ether and diisopropyl ether, C 1s, N 1s and O 1s core excitation of urea, N-phenyl urea, N,N’diphenyl urea, ethyl carbamate, N-phenyl carbamate, Nphenyl N-methyl carbamate and benzyl carbamate were derived from gas phase electron energy loss spectra. Extended Hueckel Molecular Orbital calculations were used to assist assignment and to interpret the effect of pielectron delocalisation on the gas phase spectra. Functional group identification by core excitation was explored with the aim of using core excitation spectra for microanalysis of PU polymers. 43 refs. (Pt.I, ibid, p.1593602) USA

Accession no.559042 Item 268 Journal of Polymer Science : Polymer Physics Edition 33, No.11, Aug.1995, p.1593-602 ANALYSIS OF POLYURETHANES USING CORE EXCITATION SPECTROSCOPY. I. MODEL POLYURETHANE FOAM POLYMERS Urquhart S G; Hitchcock A P; Leapman R D; Priester R D; Rightor E G McMaster University; US,National Institutes of Health; Dow Chemical USA The C 1s, N 1s and O 1s excitation spectra of model MDI PUs with well-known structures were recorded using electron energy loss spectroscopy (EELS) in an electron microscopy. These spectra were compared with the core excitation spectra of selected small molecule analogue species (recorded by gas phase EELS) in order to identify transitions characteristic of various structural components found in PUs. Spectral features characteristic of the different structural components in PUs were identified in the spectra of the model polymers. These could be used as the basis for chemical studies of micron or submicron sized segregated phases in flexible PU polymers. 27 refs. USA

Accession no.559041 Item 269 China Synthetic Rubber Industry 18, No.4, 1995, p.200-3 Chinese INFRARED SPECTRAL ANALYSIS OF HYDROGEN BONDING IN POLYURETHANE Luo Ning; Wang Dening; Ying Shengkang East China,University of Science & Technology A review is presented of the literature on the IR band assignment and quantitative analysis of hydrogen bonding in PUs. The basic bands in relation to hydrogen bonding in NH and C:O stretching regions are assigned. It is shown that hydrogen bonding cannot be adequately analysed using the NH stretching region because the features of this region include large band numbers, serious band

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overlap and large variable absorptivity coefficients with band frequency. There are at least three bands in the carbonyl stretching region. The variation of absorptivity coefficient is small so that hydrogen bonding can be analysed in the carbonyl region. 25 refs. CHINA

Accession no.557975 Item 270 Progress in Rubber and Plastics Technology 11, No.2, 1995, p.154-70 USING TIME RESOLVED X-RAY DIFFRACTION AT SYNCHROTRON RADIATION SOURCES TO STUDY STRUCTURE DEVELOPMENT IN POLYMER PROCESSING Ryan A J UMIST; EPSRC-DRAL Recent developments in time resolved X-ray scattering from polymers are reviewed in the context of structure development in polymer processing. The use of fast SAXS/WAXS and its combination with DSC is given as an example of the use of synchrotron radiation(SR) in studying thermoplastics processing. A second example of SR in polymer processing relates to the in-situ measurement of structure development in PU foam formed by reaction injection moulding of thermosets. 49 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.556245 Item 271 Analytical Chemistry 67, No.12, 15th June 1995, p.97R-126R ANALYSIS OF SYNTHETIC POLYMERS AND RUBBERS Smith C G; Smith P B; Pasztor A J; McKelvy M L; Meunier D M; Froelicher S W Dow Chemical USA A detailed review is presented of the literature on techniques for characterisation and analysis of rubbers and synthetic polymers, copolymers and blends. Chromatographic techniques such as gas chromatography, inverse gas chromatography, pyrolysis gas chromatography, and liquid chromatography, including size exclusion chromatography, are included, together with references to mass spectrometry, IR, Raman and NMR spectroscopies, and thermal techniques such as TGA and DSC. Applications include structure determination, separation and quantification of residual monomers and additives, determination of molec.wt. and study of degradation mechanisms and other thermal properties of synthetic polymers and rubbers. 1009 refs. USA

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Item 272 Analytical Chemistry 67, No.12, 15th June 1995, p.33R-46R COATINGS Anderson D G Witco Corp. A detailed review is presented of the literature published since the last review in 1993 on analytical techniques applicable to the examination of coatings and coating raw materials and to substrates on which the coatings are placed. Techniques considered include chemical and electrochemical techniques, gas chromatography, GPC, high-performance liquid chromatography, atomic absorption and plasma emission spectroscopy, IR spectroscopy, NMR spectroscopy, surface analysis, UVvisible spectroscopy, miscellaneous spectroscopic techniques, microscopy and X-ray techniques, thermal analysis, environmental and industrial hygiene studies, and miscellaneous measurements (including physical tests). 751 refs. USA

Accession no.556195 Item 273 Polyurethanes ’94. Conference proceedings. Boston, Ma., 9th-12th Oct.1994, p.381-3. 43C6 MONITORING THE PRODUCTION OF POLYURETHANES WITH NEAR-INFRARED SPECTROSCOPY Hall J W; DeThomas F A NIRSystems Inc. (SPI,Polyurethane Div.) By the use of near-infrared instrumentation designed specifically for the process environment, the isocyanate content of a urethane polymerisation reaction is monitored in real-time. A standard error of prediction of 0.15% is achieved. Real-time chemical process and analysis yields improvement in product consistency and quality while maximising process efficiency. 4 refs. USA

Accession no.555628 Item 274 Polyurethanes ’94. Conference proceedings. Boston, Ma., 9th-12th Oct.1994, p.280-5. 43C6 IMPROVED TECHNIQUE FOR THE DETERMINATION OF ISOCYANURATE AND ISOCYANATE CONVERSION BY PHOTOACOUSTIC FTIR Bhattacharjee D; Engineer R Dow Chemical Co. (SPI,Polyurethane Div.) Conventional rigid polyisocyanurate foams blown with HCFC-141b often suffer from poorer compressive strengths, dimensional stability and inferior inflammability properties when compared to foams blown

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with CFC-11. An improved isocyanurate conversion test by photoacoustic Fourier Transform Infra Red technique is introduced. The method is not limited to polyisocyanurate foam, as isocyanate conversion is an important parameter to follow in PU foams as well, especially in all carbon dioxide blown foams. The method is found to be quite reproducible and further statistical analysis to ensure the validity of this technique is under way. 8 refs. USA

Accession no.555511 Item 275 Polymer Science Series A 37, No.4, April 1995, p.462-6 MOLECULAR MASS DISTRIBUTION OF POLYMERS BY DYNAMIC LIGHT SCATTERING Klyubin V V Lebedev,Institute of Synthetic Rubber A new method is proposed for determination of the MWD of polymers; this method is based on dynamic light scattering measurements in dilute polymer solutions. Under certain conditions, the method requires no precalibration with respect to the set of monodisperse fractions. A procedure is developed for the mathematical treatment of the autocorrelation function of a photocurrent induced by light scattered from polymer coils. The optimum values of the regularisation parameter involved in the MWD calculation were determined by computer simulation for various errors of measurements of the autocorrelation function. The method was used to measure the MWD of three PMMA samples in a mixed (methyl ethyl ketone-isopropanol) solvent. The results agree well with the MWD determined by GPC. 52 refs. RUSSIA

Accession no.554646 Item 276 Polymer News 20, No.6, June 1995, p.181-2 POLYMER ANALYSIS AND CHARACTERISATION. LONG CHAIN BRANCHING: CHARACTERISATION HELPS, DOES NOT CLOSE Garbassi F EniChem SpA; Istituto Guido Donegani SpA This short review examines characterisation methods for long chain branching; their answers often need a crosscheck control, particularly when low branching degrees occur. NMR, size exclusion chromatography-multi-angle laser light scattering and rheological methods appear to be the most suitable for doing this job. 6 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; WESTERN EUROPE

Accession no.554471

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References and Abstracts

Item 277 Journal of Coatings Technology 67, No.844, May 1995, p.67-70 ALKYD-BASED THERMOSETTING RESINS: INFLUENCES OF TEMPERATURE AND UV RADIATION ON CURING KINETICS Delahaye N; Saiter J M; Liziard M; Podgorski L Rouen,University The rate of cure of different oxidative-drying oil-modified alkyd resins was investigated by DSC measurements. The studies were carried out in the presence and absence of UV light. The apparent activation energy of the curing process was determined from the Kissinger equation. This activation energy depends on the curing duration and on the illumination. These variations lead to a time constant that is characteristic of the curing kinetics. Two particular values of the apparent activation energy are also defined. 7 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.553330 Item 278 American Industrial Hygiene Association Journal 56, No.3, March 1995, p.284-9 SAMPLING AND ANALYSIS OF ISOCYANATES IN SPRAY-PAINTING OPERATIONS Rudzinski W E; Dahlquist B; Svejda S A; Richardson A; Thomas T Southwest Texas,State University; Keesler Medical Center; US,Air Force Academy; Brooks Air Force Base Detailed information is presented on methods for the sampling and analysis of airborne 1,6-hexamethylene diisocyanate (HDI) and polyisocyanates during spray painting operations. A comparison was made between Occupational Safety & Health Administration (OSHA) Method 42 and National Institute for Occupational Safety & Health (NIOSH) Method 5521. It is reported that the NIOSH Method 5521 appeared to give higher results than the OSHA Method 42 for the HDI monomer analysis, especially when the total particulate concentration is high. 26 refs. US,OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION; US,NATIONAL INSTITUTE FOR OCCUPA.SAFETY & HEALTH USA

Accession no.551818 Item 279 Trends in Polymer Science 3, No.5, May 1995, p.144-5 FUTURE DIRECTIONS FOR VIBRATIONAL SPECTROSCOPY IN POLYMER SCIENCE Krimm S Michigan,University The potential for further progress in the use of vibrational spectroscopic methods (IR and Raman) for analysis of

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polymer structure is considered. The need to improve two key components of the calculations, the force field, for obtaining band frequencies, and the dipole and polarisability derivatives, for predicting band intensities, is discussed. The use of molecular mechanics potential energy functions is examined. 11 refs. USA

Accession no.551801 Item 280 Journal of Advanced Materials 26, No.3, April 1995, p.49-54 COMPARISON OF TG VALUES FOR A GRAPHITE EPOXY COMPOSITE BY DIFFERENTIAL SCANNING CALORIMETRY(DSC), THERMOMECHANICAL ANALYSIS(TMA) AND DYNAMIC MECHANICAL ANALYSIS(DMA) O’Neal H R; Welch S; Rogers J; Guiford S; Curran G; Menard K P Lockheed Aerospace Corp.; Perkin-Elmer Corp. The effect of sample environment and test method on the apparent Tg of graphite-epoxy composites was investigated by TMA, DSC and DMA. Samples were prepared under controlled conditions and stored in a controlled environment before testing. Specimens were examined by TMA in penetration, flexure and thermal expansion, as well as by DSC and DMA in both flexure and torsion beam. The measured Tg was found to be affected by moisture content, the instrument used and the test method selected. Recommendations for the comparison of Tg values are discussed. 9 refs. USA

Accession no.551759 Item 281 Macromolecules 28, No.8, 10th April 1995, p.2797-806 STUDY OF REACTION KINETICS BY NEARINFRARED SPECTROSCOPY. II. COMPARISON WITH DIELECTRIC SPECTROSCOPY OF MODEL AND MULTIFUNCTIONAL EPOXY/ AMINE SYSTEMS Mijovic J; Andjelic S; Yee C F W; Bellucci F; Nicolais L New York,Polytechnic University; Napoli,Universita An investigation of the kinetics of two non-polymerforming epoxy/amine model systems and a polymerforming multifunctional epoxy/amine formulation (Epon 825 plus 4,4'-methylenedianiline) was carried out by dielectric and near-IR spectroscopy. Dielectric measurements were performed in the frequency range where polarisation by charge migration is the dominant mechanism and the extent of reaction was calculated from the measured variation in impedance during reactions. Near-IR spectroscopy was carried out in the frequency range between 7100 and 4000/cm, and the extent of

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reaction was evaluated from the changes in the characteristic absorption peaks. Kinetic results determined by dielectric and near-IR spectroscopy were in excellent agreement for all systems investigated. 19 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; USA; WESTERN EUROPE

Accession no.550458 Item 282 Macromolecules 28, No.8, 10th April 1995, p.2787-96 STUDY OF REACTION KINETICS BY NEARINFRARED SPECTROSCOPY. I. COMPREHENSIVE ANALYSIS OF A MODEL EPOXY/AMINE SYSTEM Mijovic J; Andjelic S New York,Polytechnic University The model compounds were 1,2-epoxy-3-phenoxypropane and aniline. In addition other materials were used to help assign different absorption peaks observed in the course of the investigation. These included epoxy resin monomers, i.e. bisphenol A diglycidyl ether and tetraglycidyl diaminophenyl methane and amine curing agents, i.e. 4,4'methylenedianiline and diaminodiphenyl sulphone. A comprehensive account of the origin, location, and shifts during reaction of all major adsorption peaks in the spectral range between 4000 and 7100/cm is provided. Reaction kinetics derived from the near-IR data were in excellent agreement with the results obtained by high performance liquid chromatography. There was a discrepancy between the kinetic predictions of near-IR and mid-IR analyses. It was established that the kinetics of epoxy/amine reactions can be accurately deduced from the near-IR data, while the standard mid-IR epoxy absorption band at 915/cm was not a unique measure of the epoxy concentration, and hence its utilisation in kinetic calculations is questionable unless appropriate corrections are made. Evidence was presented for the formation of hydrogen bonding that is directly related to a critical viscosity of the reactive mixture. 19 refs. USA

Accession no.550457

value of sample heating and cooling, the uses of the technique in the fields of polymer characterisation, pharmaceutical analysis and biochemical identification are highlighted. Fourier Transform Raman studies on surfaces, gases and inorganic systems are also discussed. The review concludes with a critical consideration of the use of alternative wavelengths to 1064 nm (that of the neodymium yttrium aluminium garnet laser) in the future development of the field. 41 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.548982 Item 284 Macromolecules 28, No.7, 27th March 1995, p.2506-11 CURE CHARACTERISATION IN DIAMINECURED EPOXY AND POLYIMIDE BY UV REFLECTION SPECTROSCOPY Jae-Woong Yu; Chong Sook Paik Sung Connecticut,University UV specular reflection spectroscopy was investigated for the characterisation of cure reactions in aromatic diamine cured epoxy resins and their composites, as well as in the imidisation characterisation of an aromatic polyamic acid. The imidisation of a polyamic acid made from 1,4phenylenediamine and an aromatic dianhydride, the spectral deconvolution of the UV reflection spectra provides a way to determine the relative composition of polyamic acid and polyimide. The resulting extent of imidisation was compared with the result by IR analysis. 15 refs. USA

Accession no.548933 Item 285 Journal of Polymer Science : Polymer Physics Edition 32, No.3, Feb.1994, p.395-408 TOUGHENING OF A HIGHLY CROSS-LINKED EPOXY RESIN BY REACTIVE BLENDING WITH BISPHENOL A POLYCARBONATE. I. FTIR SPECTROSCOPY Abbate M; Martuscelli E; Musto P; Ragosta G; Scarinzi G CAMPEC; Italy,National Research Council

Item 283 Analyst 120, No.4, April 1994, p.985-91 ROUTINE ANALYTICAL FOURIER TRANSFORM RAMAN SPECTROSCOPY. II. AN UPDATED REVIEW Hendra P J; Wilson H M M; Wallen P J; Wesley I J; Bentley P A; Arruebarrene-Baez M; Haigh J A; Evans P A; Dyer C D; Lehnert R; Pellow-Jarman M V Southampton,University

A highly crosslinked epoxy resin was modified by reactive blending with bisphenol A polycarbonate. The bisphenol A polycarbonate was dissolved at high temperature in the uncured epoxy resin before the curing process. The physical and chemical interactions between the two components were studied by FTIR spectroscopy and the reaction mechanisms were discussed. FTIR isothermal measurements showed that the presence of polycarbonate did not affect the overall curing mechanism but decreased both the initial reaction rate and the final conversion of reactants. 13 refs.

An update is given on an earlier paper published in 1989 and a summary given of the contemporary value of Fourier Transform Raman spectroscopy as an analytical tool. The

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Item 286 Polymer 36, No.4, 1995, p.775-9 SURFACE ORGANISATION OF POLYURETHANES OBSERVED BY STATIC SECONDARY ION MASS SPECTROMETRY Shard A G; Davies M C; Tendler S J B; Jackson D E; Lan P N; Schacht E; Purbrick M D Nottingham,University; Ghent,University; Kodak Ltd. Static secondary ion mass spectroscopy was used to study orientation effects at the surfaces of segmented PUs. The presence of hard segments at the polymer surface was found to be dependent on the method of sample preparation. Spin casting could produce a larger hard segment content than straightforward solvent evaporation and films produced by spin casting slowly reorganised to remove hard segments from the top 10A or so. The occurrence of such effects was restricted to polymers with high polypropylene oxide content in the soft segment and a reasonably large (above about 2500) soft segment molec.wt. 36 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.542807 Item 287 Journal of Polymer Science : Polymer Physics Edition 33, No.3, Feb.1995, p.433-43 IMPEDANCE SPECTROSCOPY OF REACTIVE POLYMERS. II. MULTIFUNCTIONAL EPOXY/ AMINE FORMULATIONS Bellucci F; Valentino M; Monetta T; Nicodemo L; Kenny J; Nicolais L; Mijovic J Napoli,Universita; New York,Polytechnic University Dielectric measurements were used to follow the advancement of cure in a bifunctional epoxy/amine formulation. In deference to earlier dielectric studies of cure, complex impedance was measured and used to calculate ionic resistivity. By using complex impedance it was possible to separate, according to their frequency dependence, the contributions to overall polarisation from electrode blocking layers, mobile charge carriers, and dipole relaxations. At any stage of cure, there is a unique frequency at which ionic resistivity can be singularly measured. 22 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; ITALY; USA; WESTERN EUROPE

Accession no.542076 Item 288 Urethanes Technology 11, No.6, Dec.1994/Jan.1995, p.16 CLEAR VIEW OF FOGGING Recent tests using Fourier Transform IR spectroscopy and gas chromatography have identified cyclic esters, formed in the manufacture of polyester polyols, and an

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antioxidant used to stabilise polyols, as the two main causes of ‘fogging’ - the creation of deposition on car windscreens. The article supplies very brief details of the findings. INOLEX CHEMICAL CO. USA

Accession no.539895 Item 289 Adhesives Age 37, No.13, Dec.1994, p.44-6 NEW TECHNIQUE FOR IN SITU CHARACTERISATION OF PSAS Li Z F; Callahan R F; Hanson C Solomat TA Instrumentation The use is discussed of thermally stimulated current (TSC), and relaxation map analysis (RMA), as practical techniques for the characterisation of pressure-sensitive adhesive systems. The global TSC can measure Tg insitu for PSAs on substrates, while RMA based on the thermal windowing technique resolves the global relaxation process into elementary Debye relaxation processes, and offers an in-depth analysis of every relaxation mode, and therefore the fine structure of the adhesive. 8 refs. USA

Accession no.536116 Item 290 Chemistry & Industry No.17, 5th Sept.1994, p.668 FIRST FOR RAMAN SPECTROSCOPY The US Armed Forces Institute of Pathology (AFIP) claims to be the first to use Raman spectroscopy to identify silicone and other foreign materials in breast tissue. The article supplies details of a Raman microprobe which provides a non-destructive technique for examining tissue on a molecular level. The article includes brief details of three different types of breast implants analysed using Raman spectroscopy. US,FOOD & DRUG ADMINISTRATION; US,ARMED FORCES INSTITUTE OF PATHOLOGY USA

Accession no.533709 Item 291 Polymer 35, No.22, 1994, p.4743-9 TOUGHENING BEHAVIOUR OF RUBBERMODIFIED THERMOPLASTIC POLYMERS INVOLVING VERY SMALL RUBBER PARTICLES. I. A CRITERION FOR INTERNAL RUBBER CAVITATION Dompas D; Groeninckx G Leuven,Catholic University

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The criteria for internal cavitation of rubber particles were evaluated. It was shown that internal rubber cavitation could be considered as an energy balance between the strain energy relieved by cavitation and the surface energy associated with the generation of a new surface. The model predicted that there existed a critical particle size for cavitation. Very small particles (100-200 nm) were not able to cavitate. This critical particle size concept explained the decrease in toughening efficiency in different rubber-modified systems involving very small particles. 35 refs. BELGIUM; EUROPEAN COMMUNITY; EUROPEAN UNION; WESTERN EUROPE

Accession no.533326 Item 292 Trends in Polymer Science 2, No.11, Nov.1994, p.391-8 TGA-FTIR: A SYNERGISTIC COMBINATION Mittleman M L; Johnson D; Wilkie C A Dayton,University; Applied Systems Inc.; Marquette,University A review is given of the role of the technique of coupling thermogravimetric analysis with IR spectroscopy to determine the pathways by which polymers degrade. 77 refs. USA

Accession no.532663 Item 293 Analytical Chemistry 66, No.19, 1st Oct.1994, p.3267-73 CHARACTERISATION OF (METHOXYMETHYL)MELAMINE RESINS BY LIQUID CHROMATOGRAPHY/MASS SPECTROMETRY Chang T T Cytec Industries The above resins are complex mixtures of melamines with different degrees of hydroxymethylation and methoxymethylation. Despite the extensive industrial use of such resins, characterisation has proved difficult because of their complex compositions. Following the development of an efficient high-performance liquid chromatography separation procedure, liquid chromatography/mass spectrometry was used for identification of separated components. Structures were assigned from molec.wt. and fragmentation information. Twenty monomeric compounds and 13 dimeric compounds were identified. 9 refs. USA

Accession no.532071 Item 294 Macromolecules 27, No.19, 12th Sept.1994, p.5428-39

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SYNCHROTRON SAXS STUDY OF STRUCTURE DEVELOPMENT KINETICS DURING THE REACTIVE PROCESSING OF FLEXIBLE POLYURETHANE FOAM Elwell M J; Mortimer S; Ryan A J UMIST Forced-adiabatic, time-resolved synchrotron small-angle X-ray scattering was used to study the microphase separation behaviour of water blown flexible PU foam, based on MDI and a polyether polyol, during reaction injection moulding. Microphase separation occurred at a critical conversion of isocyanate functional groups, and was shown to follow the kinetics associated with spinodal decomposition. The scattering data were analysed in terms of a time dependent Ginzburg-Landau model. 35 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.532056 Item 295 Polymer International 35, No.2, Oct.1994, p.119-33 USE OF INVERSE GAS CHROMATOGRAPHY TO QUANTIFY INTERACTIONS IN AMINE CURED EPOXY RESINS Jackson P L; Huglin M B; Cervenka A Salford,University; Billiton Research BV Flory-Huggins interaction parameters were determined for a series of probes in an amine cured epoxy resin matrix and its precursors by inverse gas chromatography. Hildebrand-Scatchard theory was combined with FloryHuggins theory to estimate infinite dilution solubility parameters for the matrix and its precursors at 298 K. The solubility parameters estimated by inverse gas chromatography are in good agreement with those calculated by other methods. 41 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; UK; WESTERN EUROPE

Accession no.531671 Item 296 Journal of Adhesion 46, Nos.1-4, 1994, p.227-41 ZINC COATED STEEL/EPOXY ADHESIVE SYSTEMS: INVESTIGATION OF THE INTERFACIAL ZONE BY FTIR SPECTROSCOPY Gaillard F; Romand M; Verchere D; Hocquaux H CNRS; IRSID Unieux FTIR spectroscopy was used for the analysis of ultrathin organic films on metals. FTIR in the reflection mode (IRRAS) was used to study the interaction of ultrathin films of dicyandiamide (hardener of most one-pack epoxy resins) with various substrates, model ones such as gold or zinc and industrial ones such as steel and zinc-coated steels. Pure zinc surfaces and, to a lesser extent, zinc-

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References and Abstracts

coated steels are shown to react with dicyandiamide after heating at 180 C, as evidenced by the frequency shift of the absorption band characteristic for nitrile groups. Some mechanically tested specimens are then analysed, after failure, by FTIR microspectrometry. The spectra obtained, corresponding to the fracture initiation zone which is about 100 micrometers in diameter, indicate the presence of an ultrathin layer of modified polymer still covering the substrate. 28 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; FRANCE; WESTERN EUROPE

Accession no.531582 Item 297 Journal of Applied Polymer Science 53, No.10, 6th Sept.1994, p.1351-6 GPC AND HPLC CHARACTERISATION OF UNSATURATED POLYESTER RESINS Podzimek S; Hyrsl J SYNPO AS A report is presented on the characterisation of unsaturated polyester resins by conventional GPC, GPC coupled with multi-angle laser light scattering detection, and reversedphase high performance liquid chromatography(HPLC). The ability of particular methods to analyse unsaturated polyester resins is demonstrated with reference to several examples. 9 refs. CZECH REPUBLIC

Accession no.525918 Item 298 Polymer Engineering and Science 34, No.12, June 1994, p.1025-32 FIBRE OPTIC INTRINSIC FLUORESCENCE FOR IN-SITU CURE MONITORING OF AMINE CURED EPOXY AND COMPOSITES Hyung-Joon Paik; Nak-Ho Sung Tufts University The cure reactions of epoxy-diamine and its composites are monitored in-situ using the intrinsic fluorescence of the aromatic diamine, diaminodiphenyl sulphone (DDS). With a fibre optic fluorimeter, in-situ cure monitoring was performed via a single fibre, distal-end probe, in neat epoxy as well as in commercial grade prepregs containing graphite fibres and DDS curing agent. The prepregs were investigated during multi-ply lamination in an oven. The fluorescence excitation spectra were obtained by emitting at 420 nm with a scan range of 320-400 nm, and the DDS peak position was determined as a function of cure time and temperature. 20 refs. USA

Accession no.521565 Item 299 SAMPE Journal 30, No.4, July/Aug.1994, p.38-44

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INSPECTION OF COMPOSITE STRUCTURES. I. Seidl A L United Airlines A review is given of aspects of composites analysis with emphasis placed on aircraft structures. Details are given of inspection functions, methods and techniques, including visual, lap test, penetrant, and radiographic inspection. 10 refs. USA

Accession no.521069 Item 300 Composites 25, No.7, Aug.1994, p.745-51 DEFORMATION MICROMECHANICS IN ARAMID/EPOXY COMPOSITES Andrews M C; Day R J; Patrikis A K; Young R J UMIST; Manchester,University A preliminary report on the application of Raman spectroscopy to determine the distribution of fibre strain in fragmentation, pull-out and microbond test pieces is presented. Deformation-induced Raman band shifts in the fibres can be used to map the point-to-point distribution of strain along the aramid fibres inside the epoxy resin matrix from which the interfacial shear stress may be calculated. It is shown that the behaviour is consistent with that predicted by the classical shear-lag analysis at low strains, but serious deviations from the shear-lag predictions can be found at higher levels of strain, particularly when matrix yielding at the fibre/matrix interface occurs. The results show that in the three different test methods the fibres are subjected to different states of stress, and so the values of interfacial shear stress generated using conventional analyses are unlikely to be directly comparable for the three test methods. 29 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.520965 Item 301 Composites 25, No.7, Aug.1994, p.653-60 FIBRE/MATRIX INTERPHASE AND THE ADHESION MECHANISM OF SURFACETREATED TWARON ARAMID FIBRE Mahy J; Jenneskens L W; Grabandt O Akzo Research Laboratories; Utrecht,University; Akzo Aramid Fibers In order to optimise the adhesion to an epoxy matrix, Twaron aramid fibre requires a pretreatment with an epoxy/ hardener solution. The chemical composition of the pretreated fibre surface was analysed using X-ray photoelectron spectroscopy and static imaging secondary ion mass spectrometry. To this end, model epoxy monomers were synthesised and use was made of a fluorine-labelled hardener. The effects of processing steps such as ageing of

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the pretreatment solution and curing of the epoxy/hardener at the fibre surface were systematically analysed. The results show that polar interactions between the aramid and epoxy molecules play a dominant role in the interfacial adhesion mechanism. There is evidence to suggest that the epoxy layer introduced onto the surface of the Twaron filaments is inhomogeneous as a result of the processing conditions. 21 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; NETHERLANDS; WESTERN EUROPE

Accession no.520958 Item 302 FRC ’94: Fibre Reinforced Composites. Conference Proceedings. Newcastle upon Tyne, 29th-31st March 1994, p.33/133/10. 627 ANALYSIS OF COMPOSITE TEST METHODS USING RAMAN SPECTROSCOPY Young R J; Huang Y L; Gu X; Day R J UMIST (Institute of Materials) This paper discusses in some detail the use of test methods for analysis of micromechanics for carbon fibre/epoxy resin composites, and the use of Raman spectroscopy for determination of fibre strain variation with position along a carbon fibre in the resin. Araldite LY/HY 5052 epoxy resin and T50, HM-40 and surface-treated HMS-40 PANbased fibres were used in this study. It is reported that distinction between elastic deformation, shear yielding and interfacial bonding can be achieved using this method. 16 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

Accession no.518699

Item 304 Chemistry of Materials 6, No.5, May 1994, p.573-5 NATURE OF POLYIMIDE-CLAY HYBRID COMPOSITES Lan T; Kaviratna D; Pinnavaia T J Michigan,State University Polyimide-clay hybrid composites were prepared by intercalation of a polyamic acid in the galleries of a series of montmorillonites and subsequent conversion of the polyamic acid to polyimide. The composites were studied by X-ray diffraction and it was found that much of the clay was retained in an ordered intercalated state upon hybrid composition formation. The carbon dioxide permeability of the composites was also studied and it was shown that, despite the presence of a substantial fraction of highly ordered clay aggregates, the barrier film properties at low clay loadings were good. 21 refs. USA

Accession no.514226 Item 305 Analytical Chemistry 66, No.9, 1st May 1994, p.515A-21A INDUSTRIAL PROBLEM SOLVING WITH MOLECULAR SPECTROSCOPY Koenig J L Case Western Reserve University Topics discussed include the current role of molecular spectroscopy, integration and automation of analytical procedures, virtual machine analysis of a polymer sample, interactive process monitoring, determination of spatial effects, time-resolved spectroscopy, spectral sensitivity and future developments. 38 refs. USA

Item 303 FRC ’94: Fibre Reinforced Composites. Conference Proceedings. Newcastle upon Tyne, 29th-31st March 1994, p.32/132/9. 627 DEFORMATION MICROMECHANICS IN ARAMID/EPOXY COMPOSITES Andrews M C; Patrikis A K; Young R J UMIST (Institute of Materials) The application of Raman spectroscopy in the study of composite micromechanics is discussed in some detail. It is reported that factors affecting the transfer of stress from a resin matrix to a fibre can be determined by using this technique. An experiment was conducted using a commercial grade of sized aramid fibre, Kevlar 49, in a two-part, cold-curing epoxy resin matrix with different parts by weight of curing agent. 20 refs. EUROPEAN COMMUNITY; EUROPEAN UNION; UK; WESTERN EUROPE

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Accession no.512978 Item 306 Trends in Polymer Science 2, No.5, May 1994, p.153-8 TWO-DIMENSIONAL INFRARED SPECTROSCOPY - AN EXCITING NEW TOOL FOR POLYMER CHARACTERISATION Meier R DSM Research BV A detailed account of the technical features of twodimensional IR spectroscopy is given, followed by the results of applications of the technique to studies of the compatibility of polymer blends and of polymerisation reaction kinetics. Fourier transform two-dimensional IR spectroscopy and photoacoustic two-dimensional IR spectroscopy are also considered. 24 refs. EUROPEAN COMMUNITY; NETHERLANDS; WESTERN EUROPE

Accession no.512962

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References and Abstracts

Item 307 Materiaux & Techniques 82, Nos.1/2, 1994, p.65-8 French IN-SITU STUDY OF THE DEGRADATION OF PAINTED STEEL USING AN ELECTROCHEMICAL SENSOR Barreau C; Thierry D; Lecuyer C; Massinon D IRSID The atmospheric corrosion of epoxy resin coated steel was studied by an electrochemical impedance spectroscopy technique in which impedance spectra were obtained in situ using a sensor formed by depositing a gold layer on 10% of the surface of the coated metal. The sensor was used to follow the degradation of specimens during an indoor accelerated test and a cyclic laboratory test. The impedance spectra obtained provided an insight into the processes occurring at the coating-substrate interface. 8 refs. EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE

Accession no.510104 Item 308 Analyst 119, No.3, March 1994, p.455-8 AMPEROMETRIC BIOSENSOR FOR PHENOLS BASED ON A TYROSINASE-GRAPHITE-EPOXY BIOCOMPOSITE Wang J; Lu Fang; Lopez D New Mexico,State University A new biocomposite, based on the incorporation of the enzyme tyrosinase into a graphite-epoxy resin matrix, was used for the effective biosensing of phenolic compounds. The enzyme retains its bioactivity on confinement in the epoxy resin environment. This renewable (polishable) and rigid bioprobe offers convenient quantification for various phenolic substrates. The influence of various experimental variables was explored for optimum biosensing performance. 21 refs. USA

Accession no.509469 Item 309 Analytical Chemistry 66, No.7, 1st April 1994, p.403A-15A CHARACTERISATION OF ORGANIC SURFACES Perry S S; Somorjai G A California,University This report reviews the surface science techniques that appear to be most suitable for characterising organic surfaces. Thirteen techniques are discussed, many developed in recent years, that provide information about composition and structure on the molecular level: secondary ion mass spectroscopy, X-ray photoelectron spectroscopy, UV photoelectron spectroscopy, low-energy electron diffraction, high-resolution electron loss

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spectroscopy, Raman spectroscopy, FTIR, sum frequency generation, scanning tunnel microscopy, atomic force microscopy, surface force measurements, and neutron reflectivity measurements. 34 refs. USA

Accession no.509459 Item 310 SPI Composite Institute’s 48th Annual Conference. Conference Proceedings. Cincinnati,Oh., 8th-11th Feb.1993, Paper 10-C. 627 DYNAMIC MECHANICAL ANALYSIS (DMA) RHEOLOGICAL TESTING TO CHARACTERISE SMC AND PREDICT MOULDING PERFORMANCE Walsh T J; Smith C L Rockwell International Corp. (SPI,Composites Institute) Details are presented of a study to examine test methods to characterise SMC and predict material moulding performance. In particular DMA was used, to examine six different SMC products, through moulding for scrap, defect and rework rates. Also, key process parameters were monitored. USA

Accession no.506565 Item 311 European Polymer Journal 30, No.3, March 1994, p.361-8 STRUCTURAL INVESTIGATION OF EPOXY AMINE NETWORKS BY MID- AND NEARINFRARED SPECTROSCOPY Strehmel V; Scherzer T Merseburg,Technische Universitat; Merseburg,Institute of Experimental Physics The effects of epoxy amine ratio and accelerator concentration on the chemical structure of networks based on the diglycidyl ether of bisphenol A cured with 4,4'diaminodiphenylmethane using imidazole as accelerator were investigated. Mid-IR spectra of the networks gave qualitative information about the chemical structure of the networks. From near-IR spectra, the content of residual epoxy groups and the concentration of different amine structures in the networks were calculated. For quantitative analysis of the primary amine concentration in the networks, a calibration using a model system was necessary. A mixture of anisole, 1-aminophenyl-3-phenoxy-propan2-ol and aniline was therefore used. 38 refs. EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE

Accession no.503879 Item 312 Polyurethanes World Congress 1993. Conference Proceedings. Vancouver, B.C., 10th-13th Oct.1993, p.368-72. 43C6

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References and Abstracts

ORGANIC EMISSIONS AND THEIR DECAY FROM HCFC-141B BLOWN RIGID POLYURETHANE FOAM Tsuchiya Y; Kanabus-Kaminska J M Canada,National Research Council (SPI,Polyurethane Div.; SPI Canada Inc.; European Isocyanate Producers Assn.) The diffusion of blowing agents was studied by the measurement of emissions from foams. A sample of industrial HCFC-141b blown rigid polyurethane foam was tested in an ASTM standard small-scale emission test chamber for organic emissions. The results are compared with emissions of CFC-11 from three conventional polyurethane foams. Gases emitted were analysed by gas chromatography/mass spectrometry. They included degradation products of HCFC-141b. In addition to HCFC-141b, two related compounds were identified, i.e. CFC-11 and 1,1-dichloroethene. There were also several minor components which were not identified. Results show that blowing agents stay in PU foams for long time periods. Measurements are continuing on samples blown 3 years ago. 8 refs. CANADA

Accession no.502781 Item 313 Shawbury, Rapra Technology ltd., 1993, pp.122. 12ins. 22/11/93. Rapra Review Rept.No.68. Vol.6, No.8, 1993. 9111T CURE ASSESSMENT BY PHYSICAL AND CHEMICAL TECHNIQUES Willoughby B G Rapra Technology Ltd. Edited by: Dolbey R Rapra Review Report No.68 Physical and chemical monitoring methods used to evaluate the state of curing are described and critically evaluated. Comments on both practical and theoretical aspects of cure monitoring are included and the process of cure itself is considered. 510 refs. This item is available only by purchase from Rapra Technology Ltd. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.501040 Item 314 Analytical Chemistry 65, No.24, 15th Dec.1993, p.1068A-77A NONMEDICAL APPLICATIONS OF NMR IMAGING Komoroski R A Arkansas,University An assessment is given of the status and future of NMR imaging emphasising the types of information available in NMR images. The potential of nonmedical NMRI lies in its unique ability to provide noninvasive spatial mapping of a wide variety of physical and chemical

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properties in a sample. This potential can only increase as new contrast parameters are introduced and as solidstate imaging techniques and hardware, as well as environmental control, are improved. Applications described include evaluation of structure of polymers and composites and solvent diffusion in polymers. 37 refs. USA

Accession no.500919 Item 315 Angewandte Makromolekulare Chemie Vol.212, Nov.1993, p.191-200 ANALYSIS OF EPOXY RESINS BY MATRIXASSISTED LASER DESORPTION/IONISATION MASS SPECTROMETRY Pasch H; Unvericht R; Resch M Deutsches Kunststoff-Institut; Shimadzu Europe GmbH Bisphenol A-based epoxy resins were analysed by matrixassisted laser desorption/ionisation mass spectrometry. The samples were separated into their oligomers according to the degree of polymerisation and the type of functional groups. Nine different functional species were found to be present in bisphenol A-epichlorohydrin resins. For resole epoxy resins, in addition to the oligomer distribution, the distribution of methylol groups was determined. The quantitative treatment of the spectra and the determination of the average functionality and the molar mass of the samples are discussed. 8 refs. EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE

Accession no.500670 Item 316 Polymer 34, No.24, 1993, p.5099-105 WATER ABSORPTION BY AN EPOXY RESIN AND ITS EFFECT ON THE MECHANICAL PROPERTIES AND INFRA-RED SPECTRA De’Neve B; Shanahan M E R Ecole Nationale Superieure des Mines de Paris A filled epoxy resin used as a structural adhesive and based on the diglycidyl ether of bisphenol A cured with dicyandiamide was subjected, in its bulk form, to ageing at 40, 55 and 70C and about 100% relative humidity. Gravimetric viscoelastomeric and FTIR studies were effected after various times of exposure to monitor water ingress and to link variations in mechanical behaviour with chemical modifications occurring in the polymer. 34 refs. EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE

Accession no.499766 Item 317 ICCM/9. Volume 2: Ceramic Matrix Composites and Other Systems. Conference Proceedings. Madrid, 12th-16th July 1993, p.457-64. 627

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References and Abstracts

REAL TIME, IN-SITU CURE MONITORING OF ADVANCED AEROSPACE COMPOSITES USING A FIBRE OPTIC SENSOR BASED ON FTIR SPECTROSCOPY Tapanes E E; Hill A J; Rossiter P L Monash,University Edited by: Miravete A (Zaragoza,University) The development of an intrinsic silica fibre optic chemical sensor based on evanescent wave absorption is reported. This sensor, which permits remote chemical analysis by near-IR spectroscopy, was used to monitor the cure of an advanced aerospace epoxy resin composite by coupling to a Fourier transform IR spectrometer. 19 refs. AUSTRALIA; EUROPEAN COMMUNITY; SPAIN; WESTERN EUROPE

Accession no.499244 Item 318 Polyurethanes ’92. Conference Proceedings. New Orleans, La., 21st-24th Oct.1992, p.206-15. 43C6 IN-MOULD REACTION INJECTION MOULDING KINETICS VIA MID-INFRARED FIBRE OPTIC FTIR Priester R D; McClusky J V; Cortelek D I; Carleton P S; Porter J R; de Haseth J A Dow Chemical USA; Georgia,University (SPI,Polyurethane Div.)

Item 320 Munich, Hanser, 1992, pp.viii, 279. 10ins. 14/12/93. 9922 INFRARED SPECTROSCOPY OF POLYMER BLENDS, COMPOSITES AND SURFACES Garton A Connecticut,University This book concentrates on application of infrared spectroscopy for practical problem solving and features a broad range of sampling techniques encountered by the working polymer scientist. These stress quantification, recognition, and avoidance of artifacts. Application of these techniques to the characterisation of polymer blends, composites, and surfaces is reviewed and raman spectroscopy and alternative methods of obtaining vibrational spectra are also discussed. USA

Accession no.498007

Using the technique, IR spectra were obtained of the reacting RIM polymer every 0.5 to 1 second. Chemical reaction rates and morphology development were evaluated using computer-assisted spectral analysis procedures to simultaneously monitor both isocyanate disappearance and the evolution of a variety of morphological features. In mould evaluations of conventional unfilled polyurethane, polyurea and isocyanurate formulations are discussed. 23 refs.

Item 321 Polymer 34, No.21, Nov.1993, p.4506-15 FREE-RADICAL CROSSLINKING COPOLYMERISATION OF STYRENE/ UNSATURATED POLYESTER RESINS. II. ELECTRON SPIN RESONANCE STUDY Hsu C P; Lee L J Ohio,State University The nature of propagating radicals and the radical concentration during the free-radical copolymerisation of styrene/unsaturated polyester resin systems were studied by ESR spectroscopy. The hyperfine structure of the spectrum showed that there were three types of radicals in copolymerisation at low temperatures. Changes of these radical species were determined by the ESR spectrum simulation method. The behaviour of trapped radicals formed during the reaction was examined by temperature scanning. 29 refs.

USA

USA

Accession no.498971

Accession no.497650

Three methods for determining hydrolysable chlorine in epoxy resins produced from epichlorohydrin, namely the PN (Polish), DOW and ISO methods, were examined and compared. 13 refs. Translation from Polim.Tworz.Wielk., No.4-5, 1993, p.180. Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology.

Item 322 Applied Spectroscopy 47, No.10, Oct.1993, p.1631-5 RAMAN AND NEAR-INFRARED STUDIES OF EPOXY RESIN Chike K E; Myrick M L; Lyon R E; Angel S M South Carolina,University A quantitative comparison was made of Raman and Fourier transform near-IR spectroscopic (FT-NIR) techniques for the analysis of epoxy curing. The Raman technique was found to yield a linear calibration curve much like FT-NIR. Band assignments in the Raman spectrum of diglycidyl ether of Bisphenol A were carried out by studying the Raman spectra of smaller model compounds. 26 refs.

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USA

Accession no.498667

Accession no.495952

Item 319 International Polymer Science and Technology 20, No.9, 1993, p.T/72-5 DETERMINATION OF HYDROLYSABLE CHLORINE IN EPOXY RESINS Rejdych J; Penczek P

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References and Abstracts

Item 323 New York, John Wiley, 1992, pp.297. 9ins. 10/9/92. Applied Polymer Symposium 51. 91T POLYMER ANALYSIS AND CHARACTERISATION IV. PROCEEDINGS OF A SYMPOSIUM HELD BALTIMORE, MD., 28TH31ST MAY 1991 Du Pont Co.; Ecole Superieure de Phys.et Chim.Industrielles Edited by: Barth H G; Janca J Applied Polymer Symposium 51 This volume contains 22 full papers from the proceedings of this international forum for the presentation of recent advances in the field of polymer analysis and characterisation methodologies. Major themes include solution and thermodynamic properties, characterisation of branched and rigid polymers, viscometry, separations, spectroscopy, and bulk properties. EUROPEAN COMMUNITY; FRANCE; USA; WESTERN EUROPE

Accession no.495860 Item 324 Revista de Plasticos Modernos 66, No.445, July 1993, p.33-9 Spanish FOURIER TRANSFORM RAMAN SPECTROSCOPY IN THE ANALYSIS OF POLYMERS Ellis G Instituto de Ciencia y Tecnologia de Polimeros Applications of near-infrared Fourier transform Raman spectroscopy in polymer characterisation and in the study of polymerisation, curing and vulcanisation reactions and thermal degradation processes are described. Spectra are presented for a number of polymers. 56 refs. EUROPEAN COMMUNITY; SPAIN; WESTERN EUROPE

Accession no.495746 Item 325 6th International Symposium on Structural Adhesives Bonding. Conference Proceedings. Morristown, NJ, 4th-7th May 1992, p.53-9. 6A1 FIBRE-OPTIC RAMAN SPECTROSCOPY FOR EPOXY ADHESIVE CURE MONITORING Lyon R E; Myrick M L; Angel S M; Vess T M Lawrence Livermore National Laboratory (American Defense Preparedness Assn.) The curing reaction of an epoxy adhesive in a 250 micron (10 mil) bondline) is monitored using Raman spectroscopy measured over fibre optics. The adhesive consists of the diglycidyl ether of bisphenol A in combination with a polyethertriamine hardener in a 1:1 stoichiometric ratio. The extent of chemical reaction of the epoxy as a function of time is measurable through changes in peak heights of several vibrational modes. A

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Raman peak associated with a phenyl ring vibration in the epoxide component is used as an internal reference to correct for density changes and instrumental variations. Temperature measurements are made over the same fibre optics used to obtain the cure chemistry data by measuring the intensity of anti-Stokes Raman scattering from the epoxy. Both single-fibre and dual-fibre probes are evaluated. 21 refs. USA

Accession no.495544 Item 326 Journal of Applied Polymer Science 50, No.5, 5th Nov.1993, p.907-15 CARBON-13 NMR ANALYSIS METHOD FOR UREA-FORMALDEHYDE RESIN STRENGTH AND FORMALDEHYDE EMISSION Ferg E E; Pizzi A; Levendis D C Witwatersrand,University A method based on the use of carbon-13 NMR relative peak intensity ratios for different characteristic chemical groups, known or supposed to contribute to ureaformaldehyde resin strength and formaldehyde emission is presented. The method relates results obtained by carbon-13 NMR analysis of liquid UF resins with their strength, formaldehyde emission, and percent crystallinity in the resin hardened state. 10 refs. SOUTH AFRICA

Accession no.495454 Item 327 Structural Adhesives in Engineering III. Conference Proceedings. Bristol, 30th June-2nd July 1992, p.20/1-20/6. 6A1 CHEMICAL AND MECHANICAL CHARACTERISATION OF ADHESIVE MATRICES Bishopp J A; Davies L; Haslam J J Ciba-Geigy Composites (PRI,Adhesives Group) This paper identifies the techniques which are available to characterise structural adhesives and indicates how the techniques can be used as a combination “package” to “fingerprint” structural adhesive systems. Subtle differences between two structural film adhesives of very similar chemistries (modified/toughened epoxy resins curing at 170C, plus or minus 5C) were readily shown using the test methods chosen for the “package”. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.494583 Item 328 Structural Adhesives in Engineering III. Conference Proceedings. Bristol, 30th June-2nd July 1992, p.14/1-14/8. 6A1

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References and Abstracts

ROLE OF SURFACE ANALYSIS IN ADHESIVE BONDING RESEARCH Watts J F Surrey,University (PRI,Adhesives Group) The uses of X-ray photoelectron spectroscopy, Auger electron spectroscopy and secondary ion mass spectrometry in adhesive bonding research are illustrated by reference to examples concerning the adhesive bonding of aluminium, titanium and thermoplastic carbon fibre composites. 23 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.494577 Item 329 Polymer Composites 14, No.3, June 1993, p.238-46 THERMO-STIMULATED CREEP STUDY OF THE ALPHA RETARDATION MODE IN EPOXYGLASS BEADS COMPOSITES Dufresne A; Lacabanne C Paul Sabatier,Universite Thermo-stimulated creep analysis was performed to characterise the anelastic properties around the glass transition of the model system, epoxy resin/glass beads. Different interphase regions have been deliberately formed by means of a silane coupling agent and an elastomeric adduct coating. In all samples the primary retardation mode was found to be around 140C. This retardation mode was associated with the anelastic manifestation of the glass transition of epoxy resin. The relative magnitude of this mode in filled epoxy was used to estimate the interphase thickness. By applying fractional stresses the complex alpha peak was experimentally resolved and local changes of morphology in the interphase zone were evidenced in terms of mobility and kinetic of motion. This last technique allowed comparison of the length of the mobile units liberated at the glass transition as a function of the filler-matrix interphase. 29 refs. EUROPEAN COMMUNITY; FRANCE; WESTERN EUROPE

Accession no.494226 Item 330 Trends in Polymer Science 1, No.9, Sept.1993, p.280-4 NMR IN SOLID POLYMERS Segre A L; Capitani D CNR A review is presented which describes recent developments in NMR methods, particularly high resolution techniques, deuterium NMR, NMR relaxometry (pulsed low-resolution NMR), and NMR microimaging. 36 refs. EUROPEAN COMMUNITY; ITALY; WESTERN EUROPE

Accession no.494081

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Item 331 Applied Spectroscopy 47, No.9, Sept.1993, p.1337-42 TRANSIENT 2D IR CORRELATION SPECTROSCOPY OF THE PHOTOPOLYMERISATION OF ACRYLIC AND EPOXY MONOMERS Nakano T; Shimada S; Saitoh R; Noda I Nippon Bio-Rad Laboratories; Procter & Gamble Co. Transient two-dimensional IR correlation spectroscopy coupled with real-time Fourier transform IR measurement was used to analyse the reaction process of photopolymerisation systems. Data are given for acrylic and epoxy resins. 11 refs. JAPAN; USA

Accession no.493881 Item 332 Macromolecules 26, No. 18, 30th Aug. 1993, p.4818-24 FLUORESCENCE STUDIES OF DIAMINODIPHENYL SULPHONE CURING AGENT FOR EPOXY CURE CHARACTERISTICS Jian Cheng Song; Chong Sook Paik Sung Connecticut,University Fluorescence emission and excitation of 4,4'diaminodiphenyl sulphone curing agent were studied during the curing of a bifunctional epoxide (Epon 825) or a tetrafunctional epoxide (Araldite MY 721). As the curing proceeded, both the emission and the excitation spectra exhibited red shifts of about 25 nm for 4,4'diaminodiphenyl sulphone due to the conversion of the primary amine groups to tertiary amine groups. Excitation spectral shift could be easily correlated with the extent of amine reaction. The extent of epoxide reaction based on IR analysis correlated almost linearly with excitation spectral shift. The results provide a basis for cure monitoring of the epoxy-diamine networks from the intrinsic fluorescence of the diamine curing agent. 20 refs. USA

Accession no.493360 Item 333 Journal of Applied Polymer Science 49, No.11, 15th Sept.1993, p.1921-9 NOVOLAC EPOXY RESINS AND POSITRON ANNIHILATION Suzuki T; Oki Y; Numajiri M; Miura T; Kondo K; Shiomi Y; Ito Y Japan,National Laboratory for High Energy Physics; Sumitomo Chemical Co.Ltd.; Tokyo,University The positron annihilation lifetime technique was used to study the characteristics of four kinds of epoxy resins, i.e. cresol novolac, tris-hydroxyphenylmethane, tetramethylbiphenol and bisphenol A, cured with phenol

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References and Abstracts

novolac epoxy resins. Data were obtained for Tg, thermal expansion coefficients, flexural modulus, ageing effects, water absorption rates, and the volume of intermolecular space holes among the polymer chains. 26 refs. JAPAN

Accession no.492817 Item 334 Antec ’92. Plastics: Shaping the Future. Volume 2. Conference Proceedings. Detroit, Mi., 3rd-7th May 1992, p.2052-5. 012 FIBRE OPTIC RAMAN SPECTROSCOPY FOR CURE MONITORING OF ADVANCED POLYMER COMPOSITES Myrick M L; Angel S M; Lyon R E; Vess T M South Carolina,University; Lawrence Livermore National Laboratory (SPE) The potential of fibre-optic Raman spectroscopy for remote cure monitoring of composites is demonstrated by measuring the extent of chemical reaction and temperature in-situ during the cure process of an epoxy matrix used in wet-filament wound composites. Tests were carried out using single-fibre and dual-fibre probes, the latter being constructed to evaluate the sensitivity of the side-by-side fibre arrangement for epoxy cure monitoring. 20 refs. USA

Accession no.487482

Changes in the terminal epoxy, hydroxyl and amine absorption bands upon curing were followed using the above techniques. Optimum peaks for quantitative analyses and for studying reaction kinetics were identified and the utility of near-infrared spectroscopy for studying the kinetics of epoxy resin cure reactions clearly established. The ability of in-situ near-infrared spectroscopy to obtain isothermal kinetic data is also demonstrated. 12 refs. USA

Accession no.485328 Item 337 Urethanes Technology 10, No.3, June/July 1993, p.22 FOAM CHEMISTRY BY FTIR Doerner K-H Bayer AG The characterisation of foaming behaviour and curing of PU foams, and their relationships to formulation components is reported to be one of the most fundamental aspects in PU foam development. Bayer has directed considerable resources at the development of relevant measurement techniques, instruments and software for data acquisition and evaluation. This has enabled the company to gain fundamental knowledge of the various influences and so to predict the foaming behaviour and mechanical properties of a wide range of foam formulations. Details are given. EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE

Item 335 International Polymer Science and Technology 20, No.3, 1993, p.T/56-9 MOLECULAR CHARACTERISATION OF POLYMERS BY GEL PERMEATION CHROMATOGRAPHY Cholinska M; Dobrowski Z; Kaszuba A Warsaw,Dept.of Analysis & Charact.of Plast. This article discusses some research relating to molecular characterisation by GPC recently undertaken by the Department of Analysis & Characterisation. 21 refs. (Translation of Polim.Tworz.Wielk., No.11-12, 1992, p.508). EASTERN EUROPE; POLAND

Accession no.485597 Item 336 Journal of Applied Polymer Science 49, No.2, 10th July 1993, p.219-27 MID- AND NEAR-INFRARED SPECTROSCOPIC INVESTIGATIONS OF REACTIONS BETWEEN PHENYL GLYCIDYL ETHER (PGE) AND AROMATIC AMINES Fu J H; Schlup J R Kansas State University

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Accession no.484972 Item 338 Analytical Chemistry 65, No.12, 15th June 1993, p.217R-243R ANALYSIS OF SYNTHETIC POLYMERS AND RUBBERS Smith C G; Smith P B; Pasztor A J; McKelvy M L; Meunier D M; Froelicher S W; Ellaboudy A S Dow Chemical USA A detailed review is given of techniques for characterisation and analysis of rubbers and synthetic polymers, copolymers and blends. Chromatographic techniques such as inverse gas chromatography, supercritical fluid chromatography, pyrolysis-gas chromatography, liquid chromatography, size exclusion chromatography, mass spectrometry, spectroscopy (IR spectroscopy), NMR and ESR are included. Applications include structure determination, separation, and quantifying of residual monomers and additives, determination of molecular weight, and the study of degradation mechanisms and other thermal properties of synthetic polymers and rubbers. 899 refs USA

Accession no.483946

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References and Abstracts

Item 339 Analytical Chemistry 65, No.12, 15th June 1993, p.1R-11R COATINGS Anderson D G Witco Corp.

Item 342 Kautchuk und Gummi Kunststoffe 45, No.10, Oct.1992, p.832-6 German SIMPLE METHODS FOR ANALYSIS OF PLASTICS Braun D Deutsches Kunststoff-Institut

This extensive review covers analytical techniques applicable to the examination of coatings and raw materials for coatings, and substrates upon which coatings are placed, since the last review in 1991. The contents are divided into 15 analytical techniques useful in coatings characterisation. New or unique applications for established analytical techniques appear throughout the review. 678 refs.

EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE

USA

Accession no.480354

Accession no.483945 Item 340 Journal of Polymer Science : Polymer Physics Edition 31, No.7, June 1993, p.831-41 ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPIC STUDIES OF THERMALLY GENERATED FREE RADICALS IN PMR-15 POLYIMIDE RESINS Ahn M K; Stringfellow T C; Fasano M; Bowles K J; Meador M A Indiana,University PMR-15 is a high-performance thermoset polyimide resin that is used in many high-temperature applications. EPR evidence is presented of the presence of stable free radicals in post-cured PMR-15 samples. A systematic study is presented of these free radicals using EPR spectroscopy as the tool for understanding the conditions under which they are produced. 24 refs.

Simple methods for the qualitative identification of the most important polymers in plastics waste are discussed with reference to the importance of this analysis for recycling plastics. Methods for thermoplastics, thermosets and elastomers are listed. 11 refs.

Item 343 Journal of Polymer Science : Polymer Physics Edition 31, No.6, May 1993, p.677-92 FT-RAMAN INVESTIGATION OF THE THERMAL CURING OF PMDA/ODA POLYAMIC ACIDS Johnson C; Wunder S L Temple University The effect of solvent (NMP/xylene) on the curing reactions of PMDA/ODA polyamic acids was investigated in depth using Fourier transform-Raman spectroscopy. The solvent was found to have a dramatic effect both on the rate of cure and on the final extent of conversion of the ring closure reaction. The kinetic data is shown to be consistent with the concept that the amount of solvent present in the films affects the rate of imidisation. 38 refs. USA

Accession no.478344

USA

Accession no.481651 Item 341 Polymer 34, No.11, 1993, p.2445-6 INVESTIGATION OF THE INTERPHASE OF A SILANE-FINISHED GLASS FIBRE/VINYL ESTER USING A MICROSCOPIC FTIR SPECTROMETER Ikuta N; Suzuki Y; Maekawa Z; Hamada H Osaka Municipal Industrial Research Institute; Nitto Boseki Co.Ltd.; Kyoto,Institute of Technology Glass fibre strand was treated with gammamethacryloxypropyltrimethoxysilane as coupling agent and used to reinforce a vinylester resin. The interface was studied by FTIR. Silane was able to migrate into the resin and influence curing at a distance (200 micrometres) greater than the thickness of the interphase. 3 refs. JAPAN

Accession no.481357

© Copyright 2003 Rapra Technology Limited

Item 344 Journal of Applied Polymer Science 48, No.5, 5th May 1993, p.931-4 COMPLETION OF UNSATURATED POLYESTERS ANALYSIS BY FOURIER TRANSFORM IR SPECTROSCOPY Paauw M; Pizzi A Witwatersrand,University A report is presented on the identification of IR bands of a few glycols commonly used in polyester resins, with reference to their quantification by FTIR, on the quantification of neopentyl glycol and on the quantification in the resin of styrene and its derivatives. 1 ref. SOUTH AFRICA

Accession no.477805 Item 345 Polymers & Polymer Composites 1, No.2, 1993, p.125A-34A

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References and Abstracts

APPLICATION OF VIBRATIONAL SPECTROSCOPY TO THE RESEARCH AND DEVELOPMENT OF POLYMERIC MATERIALS. III. INSTRUMENTATION AND EXPERIMENTAL TECHNIQUES IN RAMAN SPECTROSCOPY Ellis G; Marco C; Gomez Fatou J M Instituto de Ciencia y Tecnologia de Polimeros The use of conventional Raman spectroscopy in the polymer industry is discussed. Raman instrumentation is described with reference to the laser source, the sample illumination system, the dispersive system and the detector. Important aspects of Raman spectroscopy are considered, including spectral bandpass, fast-scanning and multiplexing, and stray light, and two fundamental problems in use of the technique (fluorescence and background, and the experimental geometry) are discussed. Special techniques are outlined, including total internal reflection Raman spectroscopy and waveguide Raman spectroscopy and Fourier transform Raman spectroscopy. 52 refs. EUROPEAN COMMUNITY; SPAIN; WESTERN EUROPE

Accession no.477756 Item 346 Applied Spectroscopy 47, No.3, March 1993, p.341-5 MICROSCOPIC IDENTIFICATION OF SILICONE IN HUMAN BREAST TISSUES BY IR MICROSPECTROSCOPY AND X-RAY MICROANALYSIS Centeno J A; Johnson F B US,Armed Forces Institute of Pathology The results are reported of a FTIR microspectroscopy study aimed at identifying silicone fragments from PDMS prosthetics in human breast tissue. Tissue specimens were mounted on aluminium- or gold-coated microscope slides and analysed using the reflectance capabilities of the IR microscope. Use was also made of SEM and energydispersive X-ray microanalysis to establish the elemental composition and location of the foreign material. 23 refs. USA

Accession no.476053 Item 347 Polymer Testing 12, No.2, 1993, p.185-92 COMPARATIVE DSC METHOD FOR PHYSICAL AGEING MEASUREMENT OF POLYMERS Qi Z N; Wan Z H; Chen Y P Academia Sinica A method of comparative DSC is proposed for the study of physical ageing. The essentials of the technique consist of comparing the enthalpy relaxation behaviour of an aged sample with a quenched sample as reference. The accuracy of comparison is improved because of simultaneous measurement of the sample and reference

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which makes the noise of the apparatus subtractive. This technique was applied to study the influence of crosslinking on the kinetics of enthalpy relaxation of epoxy resins. 8 refs. CHINA

Accession no.474479 Item 348 Journal of Polymer Science : Polymer Chemistry Edition 31, No.4, 30th March 1993, p.1045-52 FTIR STUDIES OF POLYIMIDES. II. FACTORS AFFECTING QUANTITATIVE MEASUREMENT Pryde C A AT & T Bell Laboratories Polyimides with various structures were studied. An analysis of imide formation using the 1370/cm band (C-N stretch) in conjunction with the 1500/cm aromatic band as an internal standard appears capable of giving precise, internally consistent measurements for the most commonly used polyimide structures, for samples that are measured in transmission. Measurements of imide content in ultrathin films by grazing incidence reflection spectroscopy appear to be at least semiquantitative. 14 refs. USA

Accession no.474403 Item 349 Journal of Applied Polymer Science 47,No.11,15th March 1993,p.2005-12 USE OF LIQUID CHROMATOGRAPHY FOR THE CHARACTERISATION OF NOVOLAC RESINS Podzimek S; Hroch L Czech Res.Inst.for Synth.Resins & Lacquers Novolac resins made by condensation of phenol or pcresol with formaldehyde in various mole ratios were analysed by reversed-phase high-performance liquid chromatography and GPC. Number-average molec.wts. of phenol novolacs were determined by GPC and vapourphase osmometry and were compared. A relationship was found between the content of dihydroxydiphenylmethane(DHDPM) and Mn of phenol novolacs. The content of phenol and DHDPM in the analysed samples was determined quantitatively. The molecular nature of the novolacs synthesised from phenol or p-cresol under the same conditions was compared. A relationship was also found between the molec.wt. of phenol novolac and the TS of abrasive material based on it. 11 refs. CZECHOSLOVAKIA; EASTERN EUROPE

Accession no.473294 Item 350 Applied Spectroscopy 47,No.2,Feb.1993,p.173-9

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References and Abstracts

CHARACTERISATION OF PU FOAMS BY MIDIR FIBRE/FT-IR SPECTROMETRY de Haseth J A; Andrews J E; McClusky J V; Priester R D; Harthcock M A; Davis B L Georgia,University; Dow Chemical USA; Dow Chemical Co. The use of a mid-IR transmitting fibre to monitor the cure process of a PU foam is described. The fibre was used as an internal reflectance element to observe changes in the PU during curing. The appearance and disappearance of absorbances in the NH-stretching, carbonyl stretching, isocyanate, and isocyanurate regions were monitored. 16 refs. USA

Accession no.471774

Item 353 Pure & Applied Chemistry 64,No.11,Nov.1992,p.1789-800 CHARACTERISATION OF THE CURE OF RESINS BY DSC (TECHNICAL REPORT) Richardson M J UK,National Physical Laboratory The magnitude of the problems arising from the use of DSC to measure the heat of reaction of resins was investigated using a well-behaved system to obtain conventional data. These were combined with heat capacities of reactants and products to show how errors arise with a variety of baselines. Emphasis is placed upon the need for correct physical foundations before the cure kinetics of a particular system can be considered. 9 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Item 351 Surface Coatings International 76,No.2,Feb.1993,p.62/9 APPLICATION OF INVERSE GAS CHROMATOGRAPHY IN PAINT FORMULATION Kunaver M; Guthrie J T; Kamin F Color; Leeds,University This paper outlines the techniques of inverse gas chromatography before giving details of the experimental work involved. Much of the paper is concerned with a discussion of the results and their significance in paint performance. It is shown that inverse gas chromatography is very powerful and easy to use in the determination of certain characteristics of the constituents of certain coatings. It concludes with an outline of the further work that is necessary to complete the investigation. 8 refs. EUROPEAN COMMUNITY; SLOVENIA; UK; WESTERN EUROPE

Accession no.471375

Accession no.470436 Item 354 Journal of Applied Polymer Science 47,No.8,20th Feb.1993,p.1481-96 DEVELOPMENT OF DYNAMIC MECHANICAL METHODS TO CHARACTERISE THE CURE STATE OF PHENOLIC RESOLE RESINS Follensbee R A; Koutsky J A; Christiansen A W; Myers G E; Geimer R L Wisconsin-Madison,University; US,Dept.of Agriculture,Forest Products Laboratory A review with practical comments is given of the difficulties involved in obtaining reproducible, quantitative DMA data during the cure of aqueous phenolformaldehyde resole resins. New procedures are described, with emphasis on determination of extents of precure. Glass fibre filter material was used as substrate for the tests. Relevance to production of phenolformaldehyde bonded flakeboard is suggested. 21 refs. USA

Accession no.469847 Item 352 Polymers Paint Colour Journal 183,No.4321,13th/27th Jan.1993,p.8/16 USE OF DIFFERENTIAL PHOTOCALORIMETRY (DPC) FOR THE STUDY OF PHOTOINITIATOR SYSTEMS Groves I F; Lever T J; Hawkins N A Marlin Scientific Ltd. The application of DPC to an analysis of two samples consisting of a base oligomer with different photoinitiators is described. The results obtained revealed that the technique could be used rapidly, accurately and reproducibly to differentiate between the two photoinitiator systems employed. The one photoinitiator produced a slower cure reaction than the other. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.471326

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Item 355 Journal of Applied Polymer Science 47,No.5,5th Feb.1993,p.761-9 SURFACE STRUCTURE AND INERT SURFACE CHARACTERISTICS OF PERFLUORODECANOIC ACID-GRAFTED POLYURETHANE Dong Keun Han; Seo Young Jeong; Young Ha Kim; Byoung Goo Min Korea,Institute of Science & Technology; Seoul,National University PU sheet (Pellethane 2363-80A) was treated firstly with hexamethylene diisocyanate and secondly with perfluorodecanoic acid to improve blood compatibility. The grafted surface was studied by ATR FTIR, angulardependent ESCA, static secondary ion mass spectrometry

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References and Abstracts

and energy-dispersive X-ray analysis. The critical surface tension was only 6.9 dyne/cm due to the optimal orientation of trifluoromethyl groups to the uppermost surface. 20 refs. KOREA

Accession no.468128 Item 356 Progress in Colloid & Polymer Science Vol.90,1992,p.202-5 FOURIER TRANSFORM INFRARED SPECTROSCOPY STUDIES ON EPOXY NETWORKS Scherzer T; Strehmel V; Taenzer W; Wartewig S Merseburg,Technische Hochschule Epoxy networks based on the diglycidyl ether of bisphenol A cured with aliphatic diols of varying chain length in the presence of magnesium perchlorate or with 4,4'diaminodiphenylmethane and imidazole, respectively, were studied by FTIR spectroscopy. The effect of the accelerator on the epoxy/amine system was investigated. 10 refs. (29th Europhysics Conference on Macromolecular Physics,’Physics of Polymer Networks’,European Physics Society/Technical University Merseburg,Alexisbad/Harz, Germany, Sept.1991) EUROPEAN COMMUNITY; GERMANY; WESTERN EUROPE

Accession no.467804 Item 357 Polimery Tworzywa Wielkoczasteczkowe 37,No.11-12,1992,p.523-6 Polish COLORIMETRIC DETERMINATION OF PHENOL AND BISPHENOL-A CONCENTRATIONS IN EXTRACTS FROM EPOXY COATINGS IN CONTACT WITH FOOD Iwanska S; Leszczynska I Warsaw,Industrial Chemistry Research Institute

HIGH-RESOLUTION PYROLYSIS-GAS CHROMATOGRAPHY FOR THE STUDY OF EPOXY RESINS CURED WITH PREPOLYMERS OF VARYING MOLECULAR WEIGHT Nakagawa H; Wakatsuka S; Ohtani H; Tsuge S; Koyama T Nagoya,University; Mitsubishi Petrochemical Co.Ltd. Epoxy resins cured with prepolymers of varying molec.wt. were studied by high-resolution pyrolysis-gas chromatography. Various phenols and the glycidyl ethers of bisphenol A, characteristic of the prepolymer backbone, were observed in the pyrograms of the prepolymers. In addition, pyrolysates characteristic of the curing agents were also observed in cured resin systems. In both cases, the peak intensities changed as a function of the molec.wt. of the original prepolymers. The molec.wts. of the original prepolymers were calculated from the peak intensities of the characteristic products for the uncured prepolymers and the cured resins. 9 refs. JAPAN

Accession no.464785 Item 359 Polymer 33,No.21,1992,p.4486-92 EPOXY RESIN ANALYSIS BY FOURIER TRANSFORM MASS SPECTROMETRY: A COMPARISON OF PYROLYSIS AND LASER ABLATION Creasy W R IBM Corp.

A method for determining trace amounts of bisphenol-A (1 to 5 mg/l) and phenol (0.1 to 1 mg/l) in extracts from epoxy coatings which had come in contact with food was elaborated and described. The analysis was carried out by two colorimetric methods. The methods were based on reactions of both phenols in alkaline solution either with 4-aminoantipyrine-potassium ferricyanide (reagent 1) with the formation of red indophenols or with 2,6dichloroquinonechlorimide (reagent 2) with the formation of blue compounds. 3 refs.Articles from this journal can be requested for translation by subscribers to the Rapra produced International Polymer Science and Technology.

The pyrolysis and decomposition products of cured, fireretarded epoxy resin (diglycidyl ether of tetrabrominated bisphenol A) were compared under several different conditions, i.e. thermal pyrolysis, laser ablation and cw laser pyrolysis. Volatile neutral products were ionised by electron impact, except in the case of direct laser ionisation, and detected by Fourier transform mass spectrometry. Pyrolysis gave high molec.wt. fragments and a considerable amount of information about the monomer composition. Detection of directly ionised, laser-ablated products gave some molecular fragments from microprobe sample sizes, although the spectra were complex. Laser ablation/electron impact ionisation produced mostly low molec.wt. fragments that gave limited information about the material. Laser pyrolysis using a cw argon ion laser provided some large fragments and consumed small amounts of sample. The relationships and analytical value of these techniques are discussed. 31 refs.

EASTERN EUROPE; POLAND

USA

Accession no.467739

Accession no.464776

Item 358 Polymer 33,No.21,1992,p.4556-62

Item 360 Macromolecules 25,No.17,17th Aug.1992,p.4285-9

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References and Abstracts

CARBON-13 NMR ANALYSIS OF THE POLYMER MICROSTRUCTURE OF A CURED BISMALEIMIDE-STYRENE THERMOSET RESIN Winter H; van der Velden G P M DSM Research BV; DSM Polymers & Hydrocarbons BV 12 refs. EUROPEAN COMMUNITY; NETHERLANDS; WESTERN EUROPE

Accession no.464345 Item 361 Surface Coatings International 75,No.7,July 1992,p.256-8 FOURIER ANALYSIS OF ALKYD RESINS USING X-RAY DIFFRACTION TECHNIQUE Swarup S HARCOURT BUTLER TECHNOLOGICAL INSTITUTE Alkyd resins with long, medium and short oil lengths were analysed by X-ray diffraction and the diffraction patterns examined by Fourier analysis. The structures of the alkyd resins were correlated with physical properties, such as particle size, crystallinity and electron density fluctuations. 9 refs. INDIA

Accession no.462385 Item 362 Journal of Cellular Plastics 28,No.3,May/June 1992,p.200-17 CFC-FREE PU PIPE INSULATION FOAMS FOR USE IN DISTRICT HEATING SYSTEMS Broennum T SHELL LOUVAIN-LA-NEUVE Details are given of the effect of the total replacement of CFCs on the processing and physical properties of PU foam pipe insulation. Techniques such as thermal mechanical analysis and foam ageing experiments were used to evaluate foams produced from developmental polyols. Key parameters were heat resistance, foam softening temperature, miscibility and flow properties of the system. 2 refs. BELGIUM; EUROPEAN COMMUNITY; WESTERN EUROPE

Accession no.460942 Item 363 Polymer Bulletin 29,No.1/2,Aug.1992,p.219-23 POSSIBILITY OF DIRECT OBSERVATION OF RESIDUAL STYRENE IN CROSSLINKED POLYESTERS BY SOLID STATE CARBON-13 NMR METHODS Zhukov I;Grobelny J

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POLISH ACADEMY OF SCIENCES Cross- and direct-polarisation NMR in the solid state was used to study crosslinked polyesters. It was shown that direct-polarisation solid state NMR spectra provided evidence for the presence of residual styrene, while in the cross-polarisation experiments styrene was discriminated against due to its high mobility at ambient temp. 8 refs. EASTERN EUROPE; POLAND

Accession no.460229 Item 364 Analytical Chemistry 64,No.12,15th June 1992,p.428R-42R SIZE EXCLUSION CHROMATOGRAPHY Barth H G;Boyes B E DU PONT DE NEMOURS E.I.,& CO.INC. A literature review is given of developments in sizeexclusion chromatography for 1989 to 1991. Emphasis was given to high-performance SEC although studies utilising conventional packings were included if they were of fundamental significance or dealt with an unusual separation. 467 refs. USA

Accession no.460145 Item 365 Analytical Chemistry 64,No.12,15th June 1992,p.389R-407R CAPILLARY ELECTROPHORESIS Kuhr W G;Monnig C A CALIFORNIA,UNIVERSITY A literature review is presented on developments in capillary electrophoresis during 1990 and 1991. Other electrophoretic techniques are included only where they have a direct influences on capillary electrophoretic methods. 523 refs. USA

Accession no.460144 Item 366 Analytical Chemistry 64,No.12,15th June 1992,p,.353R-89R LIQUID CHROMATOGRAPHY: THEORY AND METHODOLOGY Dorsey J G;Foley J P;Cooper W T;Barford R A;Barth H G CINCINNATI,UNIVERSITY; DU PONT DE NEMOURS E.I.,& CO.INC.; FLORIDA STATE UNIVERSITY; US,DEPT.OF AGRICULTURE; VILLANOVA,UNIVERSITY A literature review is given which covers developments in liquid chromatography from 1989 to 1991. 1170 refs. USA

Accession no.460143

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References and Abstracts

Item 367 Analytical Chemistry 64,No.12,15th June 1992,p.302R-20R SURFACE ANALYSIS: X-RAY PHOTOELECTRON SPECTROSCOPY AND AUGER ELECTRON SPECTROSCOPY Turner N H;Schreifels J A GEOCENTERS INC.; US,NAVAL RESEARCH LABORATORY A literature review is presented on X-ray photoelectron spectroscopy and Auger electron spectroscopy between 1989 and 1991. 490 refs. USA

Accession no.460142 Item 368 Analytical Chemistry 64,No.12,15th June 1992,p.270R-302R INFRARED SPECTROMETRY Putzig C L;Leugers M A;McKelvy M L;Mitchell G E;Nyquist R A; Papenfuss R R;Yurga L DOW CHEMICAL CO. A literature review is given for aspects of IR spectrometry that are relevant to chemical analysis between 1989 to 1991. A few selected references to FT-Raman spectrometry are included. 1063 refs. USA

Accession no.460141 Item 369 Analytical Chemistry 64,No.12,15th June 1992,p.243-54R NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY Haw J F TEXAS,A & M UNIVERSITY A literature review is presented of the coverage of NMR spectroscopy of solids and chemical applications. 687 refs. USA

Accession no.460140 Item 370 Analytical Chemistry 64,No.12,15th June 1992,p.170R-80R GAS CHROMATOGRAPHY Eiceman G A;Clement R E;Hill H H NEW MEXICO,STATE UNIVERSITY; ONTARIO,MINISTRY OF THE ENVIRONMENT; WASHINGTON STATE,UNIVERSITY A literature review is given of developments in gas chromatography covering 1990 and 1991. The related technique of gas chromatography-mass spectrometry is also included. The principles of and rationale for the characterisation of liquid phases and for the

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prediction of retention behaviour are mentioned. 407 refs. CANADA; USA

Accession no.460137 Item 371 Analytical Chemistry 64,No.12,15th June 1992,p.153R-70R SUPERCRITICAL FLUID CHROMATOGRAPHY AND EXTRACTION Chester T L;Pinkston J D;Raynie D E PROCTER & GAMBLE CO. A literature review is presented which includes progress in supercritical fluid chromatography, together with coupled analytical techniques. 418 refs. USA

Accession no.460136 Item 372 Analytical Chemistry 64,No.12,15th June 1992,p.147R-53R THERMAL ANALYSIS Dollimore D TOLEDO,UNIVERSITY A literature review is given on thermal analysis techniques reported between December 1989 to November 1991. Topics mentioned include thermodynamics, reaction kinetics, medical and pharmaceutical studies, and minerals. 264 refs. USA

Accession no.460135 Item 373 SAMPE Journal 28,No.4,July/Aug.1992,p.37-42 EPOXY CURE MONITORING USING FIBREOPTIC RAMAN SPECTROSCOPY Myrick M L;Angel S M;Lyon R E;Vess T M LAWRENCE LIVERMORE NATIONAL LABORATORY The curing of an epoxy matrix used for wet-filamentwound composites was monitored using Raman spectroscopy measured over fibre optics. The extent of the reaction of the epoxy resin (DER 332) as a function of time was measured through changes in peak heights of several vibrational modes. Temperature measurements were made over the same fibre optics used to obtain the cure chemistry data by measuring the intensity of anti-Stokes Raman scattering from the epoxy resin. Both single-fibre and dual-fibre probes were evaluated. 20 refs. USA

Accession no.460085

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References and Abstracts

Item 374 Analytical Chemistry 64,No.12,15th June 1992,p.1R-22R NUCLEAR AND RADIOCHEMICAL ANALYSIS Ehmann W D;Robertson J D;Yates S W KENTUCKY,UNIVERSITY A literature review is given emphasising topics representing the use of nuclear properties for chemical and elemental analysis. 800 refs. USA

Accession no.460079 Item 375 Fire & Materials 16,No.2,April-June 1992,p.101-3 COMMUNICATION: HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY TO IDENTIFY MELAMINE IN ORDER TO DIFFERENTIATE BETWEEN COMBUSTION MODIFIED AND TRADITIONAL POLYURETHANE FOAM Cody M K;Patterson I D UK,LABORATORY OF THE GOVERNMENT CHEMIST A high-performance liquid chromatography method for the identification and quantification of melamine in PU foam is described. Results of a trial of this method show a correlation between the presence of combustionmodifying chemicals in the PU foam and its compliance with the Furniture and Furnishings (Fire) (Safety) Regulations 1988. The method is shown to provide a rapid means of screening materials and to be capable of supplementing the British Standard flame test. 5 refs. EUROPEAN COMMUNITY; UK; WESTERN EUROPE

Accession no.455064 Item 376 Polymer Degradation and Stability 37,No.2,1992,p.125-9 SPECTROSCOPIC STUDY OF THE MOLECULAR STRUCTURE OF A LIGNINPOLYMER SYSTEM Nada A M A;Fadly M;Dawy M EGYPT,NATIONAL RESEARCH CENTRE; HELWAN,UNIVERSITY The molecular structure of phenol-lignin formaldehyde resin was studied by means of IR and electronic spectra. The effect of the phenol:lignin ratio, temp. and the adduct (phenol-lignin):formaldehyde (PL:F) ratio on the absorption spectra of the polymer produced were investigated. The new band which appeared at 2850 cm(1) in the IR spectra of PL-F resins was assigned to the methoxyl group. More information about the molecular structure was obtained from a qualitative study of the frequency and intensity changes of the absorption. 11 refs. EGYPT

Accession no.453408

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Item 377 Polymer Engineering and Science 32,No.6,March 1992,p.409-14 RELATIONSHIPS IN A BISMALEIMIDE RESIN SYSTEM. I. CURE MECHANISMS Donnellan T M;Roylance D MASSACHUSETTS,INSTITUTE OF TECHNOLOGY; US,NAVAL AIR DEVELOPMENT CENTER USA A series of bismaleimide resin systems was examined to identify the molecular features responsible for the mechanical response of these materials. A range of network structures was produced by formulation of resins with different ratios of N,N’-bismaleimido-4,4'diphenylmethane and methylene dianiline (MDA), and by use of different thermal processing cycles. Spectrographic and chromatographic techniques were used to study the reactions that occurred during the cure. Two principal reactions were confirmed: a Michael addition reaction which provides linear chain growth, and an addition reaction which produces crosslinking through the double bonds of the maleimide group. In general, curing at a lower temp. or increasing the MDA content served to favour chain extension over crosslinking, which might be expected to increase molecular mobility in the resin. 23 refs. Accession no.452651 Item 378 Journal of Polymer Science : Polymer Physics Edition 30,No.4,30th March 1992,p.373-9 EQUILIBRATION OF MIXTURES OF POLYAMIC ACIDS STUDIED USING SIZE EXCLUSION CHROMATOGRAPHY AND LIGHT SCATTERING Cotts P M;Volksen W;Ferline S IBM ALMADEN RESEARCH CENTER The transamidation reaction in a polyamic acid solution was studied using size exclusion chromatography and low-angle light scattering. Mixtures of a high molec.wt. and a low molec.wt. polymer and of the high molec.wt. polymer with monomer were investigated. The polyamic acid examined was a product of the polycondensation of 3,3',4, 4'-biphenyltetracarboxylic acid dianhydride with oxydianiline. In all cases, the MWD equilibrated with time to a most-probable distribution with a degree of polymerisation consistent with the stoichiometry of he mixture. 17 refs. USA

Accession no.452600 Item 379 Polymer 33,No.7,1992.p.1370-3 CARBON-13 LIQUID- AND SOLID-STATE

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References and Abstracts

NUCLEAR MAGNETIC RESONANCE AND INFRA-RED STUDIES OF AMINE-CURED EPOXY RESINS Fischer A;Schlothauer K;Pfitzmann A;Spevacek J CZECHOSLOVAK ACADEMY OF SCIENCES,INST.MACR.CHEM.; MERSEBURG,UNIVERSITY The final network structure of an epoxy resin system and the course of reaction of bisphenol a diglycidyl ether with 1-cyanoguanidine as curing agent dissolved in dimethyl formamide in the presence of different accelerators were studied by liquid-state carbon-13 NMR spectroscopy, solid-state carbon-13 cross-polarisation/magic angle spinning NMR spectroscopy and IR spectroscopy. Fractions of reactive groups such as oxirane rings, primary and secondary hydroxyl groups, imide and nitrile groups were detected as functions of epoxy consumption and reaction conditions. Structural tautomerism of the curing agent, the influence of water, the reaction of nitrile groups and other structural features of the curing system were examined. 11 refs. CZECHOSLOVAKIA; EASTERN EUROPE; GERMANY

Accession no.452021 Item 380 Revista de Plasticos Modernos 63,No.428,Feb.1992,p.181-7 Spanish VIBRATIONAL SPECTROSCOPY APPLIED TO THE INVESTIGATION AND DEVELOPMENT OF POLYMERIC MATERIALS. III. INSTRUMENTATION AND EXPERIMENTAL TECHNIQUES IN RAMAN SPECTROSCOPY Ellis G;Marco C;Gomez J M INSTITUTO DE CIENCIA Y TECNOLOGIA DE POLIMEROS An examination is made of techniques and instrumentation used in conventional Raman spectroscopy, and developments in total internal reflection,waveguide and Fourier transform Raman spectroscopy are reviewed. Applications in the study of polymers and other materials are mentioned. 52 refs. EUROPEAN COMMUNITY; SPAIN; WESTERN EUROPE

Accession no.451663 Item 381 Industrial & Engineering Chemistry Research 31,No.3,March 1992,p.973-9 POLYMER SOLUTION PROPERTIES OF A PHENOL-FORMALDEHYDE RESOL RESIN BY GPC, INTRINSIC VISCOSITY, STATIC LIGHT SCATTERING, AND VAPOUR PRESSURE OSMOMETRIC METHODS Kim M G;Nieh W L;Sellers T;Wilson W W;Mays J W BIRMINGHAM,UNIVERSITY OF ALABAMA; MISSISSIPPI,STATE UNIVERSITY

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Details are given of the determination of the molecular weight and extent of branching of a wood adhesive phenol-formaldehyde resol resin synthesised by sodium hydroxide catalysis. 18 refs. USA

Accession no.451404 Item 382 Progress in Organic Coatings 20,No.1,16th March 1992,p.81-96 DISTRIBUTION OF MELAMINE IN MELAMINE/POLYESTER COATINGS: FTIR SPECTROSCOPIC STUDIES Hirayama T;Urban M W NORTH DAKOTA STATE UNIVERSITY Studies of polyester/melamine films using ATR FTIR spectroscopy indicated that the melamine distribution across the films was uniform unless the hydroxyl content was low and the cure temps. relatively high. With polyester resins having an OH number as low as 6, curing at 250C with 30 w/w% melamine gave rise to melamine enrichment at the film-air interface. Enrichment was believed to result from melamine self-condensation near the interface. The primary factor leading to selfcondensation was found to be loss of amine at the surface. Coating properties such as flexibility and stain resistance were studied. 34 refs. USA

Accession no.451356 Item 383 Antec 91.Conference Proceedings. Montreal,5th-9th May 1991,p.1170-3. 012 THERMAL CURE CHARACTERISATION BY SIMULTANEOUS DYNAMIC MECHANICAL AND DIELECTRIC MEASUREMENTS Wetton R;Marsh R;Foster G;Connolly M POLYMER LABORATORIES INC.; POLYMER LABORATORIES LTD. (SPE) If simultaneous dielectric and mechanical measurements are made on a batch of resin, a viscosity and modulus/ permittivity correlation chart can be produced. This then allows dielectric measurements made with, e.g. remote electrodes, to be converted into mechanical property data for the particular batch of resin. Such tests also serve as a quality control check for incoming resin material. 1 ref. EUROPEAN COMMUNITY; UK; USA; WESTERN EUROPE

Accession no.448695 Item 384 Journal of Polymer Science : Polymer Physics Edition 29,No.9,Aug.1991,p.1117-25 RELAXATION IN THERMOSETS. IX. IONIC CONDUCTIVITY AND GELATION OF DGEBA-

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References and Abstracts

BASED THERMOSETS CURED WITH PURE AND MIXED AMINES Mangion M B M;Johari G P MCMASTER UNIVERSITY The results obtained during the isothermal curing of DGEBA-based thermosets crosslinked with diaminodiphenyl methane and diaminodiphenyl sulphone and their mixtures were analysed to determine how dc conductivity changes with time during the conversion of the liquid to gel. The complex permittivity data are first analysed to show that ac measurements can be used to obtain the ionic conductivity over a considerable period of the curing process. 30 refs. In pt.X, an analysis is made of dipolar relaxations in the resins during isothermal cure. 32 refs. CANADA

Accession no.429827 Item 385 Journal of Polymer Science : Polymer Physics Edition 28,No.9,Aug.1990,p.1621-39 RELAXATION OF THERMOSETS. IV. DIELECTRIC STUDY OF CROSSLINKING OF DIGLYCIDYL ETHER OF BISPHENOL-A BY TWO CURING AGENTS Mangion M B M;Johari G P MCMASTER UNIVERSITY The dielectric permittivity E-1 and loss E-2 during crosslinking or curing of diglycidyl ether of bisphenol-A with diaminophenyl methane and diaminodiphenyl sulphone were measured from the sol to gel to glasstransformation regions. E-1 monotonically decreased with time; E-2 initially decreased, then increased and finally decreased to low values. E-1 and E-2 shifted to shorter times with increasing curing temps. The dielectric consequences of the chemical changes with time during the crosslinking of a thermoset are shown to be analogous to the frequency dependence of E- in an amorphous solid. Additional curing at longer times produced polymer segments in a network with a high reorientation rate. E-1 and E-2 were analysed and the role of conductivity in determining the curing system were estimated. 39 refs. CANADA

Accession no.409019 Item 386 Journal of Applied Polymer Science 41,No.1/2,1990,p.205-32 ANALYSIS OF THE FORMATION AND CURING REACTIONS OF RESOLE PHENOLICS So S;Rudin A WATERLOO,UNIVERSITY The chemical compositions and molecular size distributions of a series of soluble resole phenolics was studied by high resolution carbon-13 NMR, IR, GPC and

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viscosity (Rheometrics Mechanical Spectrometer Model 605). The curing reactions were followed by IR and solid state NMR. The ultimate degree of cure increased with curing time and temp. The molec.wt. of the precursor resole could be increased with increasing formaldehyde/ phenol mole ratio and increased reaction time and temp. The degree of cure was directly proportional to the molec.wt. of the precursor resole. The catalyst (barium hydroxide, sodium hydroxide or sodium carbonate) had a great effect on resole composition and molecular size. The type of crosslinkages (methylene or dibenzyl ether) depended on pH. 23 refs. CANADA

Accession no.408553 Item 387 European Polymer Journal 26,No.5,1990,p.541-4 SIMULTANEOUS MEASUREMENT BY ESR SPECTROSCOPY OF MONOMER CONVERSION AND RADICAL CONCENTRATION DURING POLYMERISATION FOR DETERMINATION OF KINETIC PARAMETERS Carswell T G;Hill D J T;Hunter D S;Pomery P J;O’Donnell J H;Winzor C L QUEENSLAND,UNIVERSITY Managanese oxide was used to determine the microwave absorption in an ESR spectrometer during the polymerisation of methyl methacrylate in order to measure the absolute concentration of propagating radicals. The magnetic field for the manganese resonance showed good correlation with the conversion of monomer to polymer determined by gravimetric and NMR methods. The radical concentration and the conversion could thus be measured throughout the polymerisation in a single experiment, enabling the kinetic parameters K(p) (the propagation rate constant) and K(t) (the termination rate constant) to be determined directly. 22 refs. AUSTRALIA

Accession no.400668 Item 388 SAMPE Journal 26,No.2,March/April 1990,p.19-25 FT-RAMAN CHARACTERISATION OF POLYIMIDE COMPOSITES Johnson C;Wunder S L TEMPLE UNIVERSITY Analytic Fourier Transform (FT) Raman spectroscopy has been used in the characterisation of polyimides, polyimide composites and polyimide prepregs. The technique, developed over the past five years, is discussed, together with some FT-Raman spectral data obtained from various polyimides and polyimide composites. The utility of the FT-Raman technique for composite applications is demonstrated with reference to the results. Possible future

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developments are discussed and their impact on composite characterisation and analysis is considered. 22 refs. USA

Accession no.397362

RAPRA TECHNOLOGY LTD. The synthesis and evaluation of polymer supported catalysts in the cure of carboxy-terminated polybutadiene are discussed. 18 refs. UK

Item 389 Advances in Polymer Science 51,No.80,1986,p.1-47 DIELECTRIC ANALYSIS OF THERMOSET CURE Senturia S D;Sheppard N F MASSACHUSETTS INSTITUTE OF TECHNOLOGY A review is presented of the dielectric analysis of thermoset curing. Aspects covered include dielectric measurement methods, the various instruments and electrodes and their calibration; microscopic mechanisms giving rise to the observed microscopic dielectric properties; effects of temp. and curing on these properties. A selected bibliography of applications of the dielectric analysis of thermoset curing is included. 118 refs. USA

Accession no.353575 Item 390 European Polymer Journal 23,No.2,1987,p.105-8 STUDY OF THE POLYMERISATION OF ACRYLATES USING ELECTRON BEAM RADIATION Davidson R S;Ellis R J;Wilkinson S A;Summersgill C A CITY UNIVERSITY,LONDON; WIGGINS TEAPE LTD. The formation of surface coatings by three bifunctional acrylates and one trifunctional acrylate by polymerisation induced by electron beam radiation was studied. Physical testing (solvent resistance and pencil hardness test) indicated that the properties of the coatings changed as they were exposed to increasing amounts of radiation. FTIR photoacoustic spectroscopy was used to measure the extent of double bond consumption under irradiation; it was found that reactive double bonds were consumed at relatively low doses (less than 10kGy), indicating that film properties were extensively affected by radiationinduced reactions in the polyacrylate. A new reactive diluent, dibutyltin diacrylate, was shown to cure extremely rapidly to give hard coatings. 10 refs. UK

Accession no.329821

Accession no.317602 Item 392 British Polymer Journal 18,No.3,May 1986,p.151-5 TECHNOLOGY OF PHENOL-FORMALDEHYDE MOULDING POWDERS. I. CHARACTERISATION OF NOVOLAK RESINS AND DERIVED MOULDING POWDERS Birley A W;Blinkhorn A LOUGHBOROUGH,UNIVERSITY Novolak prepolymers were characterised by GPC using an IR detector. A variety of frequencies were employed, corresponding to different components in the resin, and the best separation was obtained by monitoring the phenolic hydroxyl at 3400/cm. It was concluded that both commercial Novolak and prepolymer extracted from moulding powder contained a substantial fraction of high molec.wt. material. 12 refs. UK

Accession no.313104 Item 393 Journal of Macromolecular Science A 23,No.3,1986,p.369-79 IDENTIFICATION OF OLIGOMERS IN THE REACTION OF POLYOLS WITH ISOCYANATES BY CARBON-13 NMR AND GPC Sebenik A;Osredkar U;Vizovisek I LJUBLJANA,BORIS KIDRIC CHEMICAL INSTITUTE Kinetics and mechanism of formation of urethane, biuret, allophanate and isocyanurate in the synthesis of PUs were studied by means of carbon-13 NMR and GPC. In the spectra, the regions of urethane, allophanate, biuret and isocyanurate were used to study the mechanism of reaction between isocyanates and glycols under different reaction conditions. Urethane groups gave signals between 153 and 156ppm, isocyanate groups between 149 and 151ppm. For the determination of secondary rate constants, the well-separated signals of urethane and allophanate in the carbon-13 NMR spectra were used. 6 refs. YUGOSLAVIA

Item 391 British Polymer Journal 18,No.4,July 1986,p.266-72 CURE OF CARBOXY-TERMINATED DIENE POLYMERS AND THE ROLE OF A POLYMERSUPPORTED CATALYST Willoughby B G

132

Accession no.310960 Item 394 Journal of Polymer Science : Polymer Letters Edition 23,No.8,Aug.1985,p.403-7 STUDY OF THE CURING REACTIONS OF PHENOLIC RESINS BY HIGH FIELD CARBON-

© Copyright 2003 Rapra Technology Limited

References and Abstracts

13 CP/MAS NMR SPECTROSCOPY So S;Rudin A Cross-polarisation/magic angle spinning (CP/MAS) carbon-13 NMR measurements are shown to be suitable for following the degree of cure of resole phenolics from the CH2/Ar(1) carbon ratios. The cross-polarisation contact time may, however, have to be adjusted for different states of cure. 10 refs. CANADA

Accession no.281195 Item 395 Oxford, Pergamon Press Ltd., 1984, pp.ix,445. LS.24.50. 9ins. 2copies. 12/7/85. Analytical Chemistry Vol.8. 91T ANALYSIS OF PLASTICS Crompton T R

KINETICS BY CARBON-13 AND NITROGEN-15 NMR SPECTROSCOPY AND HPLC Grenier-Loustalot M F;Grenier P INSTITUT UNIVERSITAIRE DE RECHERCHE SCIENTIFIQUE The curing reaction of an epoxy resin based on biphenol A diglycidyl ether with metaphenylene diamine was investigated by HPLC and carbon-13 and nitrogen-15 Fourier transform NMR spectroscopy. With the results obtained from a series of models, a mechanism was proposed, and the cure kinetics were obtained at 100C. It was concluded that cure proceeded mainly by chain extension, whereas crosslinking occurred in the reaction of hydroxyl groups with epoxides and resulted in the formation of ether linkages. 17 refs. FRANCE

Accession no.268359

This book covers all aspects of the analysis of plastics by chemical and physical methods. It is divided into eight chapters which each deal with a particular polymer or group of polymers:- polyolefins, polypropylene, higher alkene polymers, styrene polymers, chlorine-containing polymers, methacrylates, polybutadienes, polyesters and polyethers. The techniques discussed include spectroscopy, chromatography, fractionation,, X-ray diffraction, autoradiography, DTA, TGA and DSC.

Item 398 Analytical Chemistry 55,No.9,Aug.1983,p.1533-7 DETERMINATION OF REACTIVE COMPONENTS IN SILICONE FOAMS Dubiel S V;Griffith G W;Long C L;Baker G K; Smith R E BENDIX CORP.

UK

Analytical methods were developed for the determination of reactive components used in the formulation of RTV silicone foams. The reactive components include total silanol, silane hydrogen, tetrapropoxysilane, and diphenylmethylsilanol. 18 refs.

Accession no.280400 Item 396 Kobunshi Ronbunshu 42,No.5,1985,p.325-31 Japanese SIZE EXCLUSION CHROMATOGRAPHY OF NOVOLACS ON POLYSTYRENE GELS IN N, NDIMETHYLFORMAMIDE Hasegawa K;Fukuda A;Tonogai S;Horiuchi H OSAKA MUNICIPAL TECHNICAL RESEARCH INSTITUTE Two kinds of novolacs having different 0-/p- ratios for methylene linkages (HPN:38/62 and HON:75/25) were characterised by size exclusion chromatography on PS gels. It was found that the novolacs exhibited unexpected chromatographic behaviour in pure DMF, which disappeared upon the addition of LiBr. 26 refs. JAPAN

Accession no.278004 Item 397 Journal of Polymer Science : Polymer Chemistry Edition 22,No.12,Dec.1984,p.4011-33 French EPOXY RESIN-AMINE CURING REACTION: STUDY OF THE REACTION MECHANISM AND

© Copyright 2003 Rapra Technology Limited

USA

Accession no.238941 Item 399 Centre de Recherche sur les Macromolecules. Proceedings of the 27th International Symposium on Macromolecules Vols.1-2 Strasbourg,July 69,1981,Vol.1,p.117-20. CONFER. 012 GELATION STUDIES USING DIISOCYANATES AND TETROLS Hirasawa Y; Stepto R F T; Still R H Previous investigations of hexamethylene diisocyanate/ tetrol systems were extended, tetrols based on the propylene oxide extension of pentaerythritol again being used, but a wider range of molec.wts. being covered. Reactions were conducted at 80C in bulk and in nitrobenzene, and equal initial concentrations of reactive groups were used. 7 refs. Accession no.217283 Item 400 Journal of Polymer Science : Polymer Chemistry Edition 17, No.23, Dec.1979, p.4123-7

133

References and Abstracts

SEPARATION AND IDENTIFICATION OF POLYETHYLENE TEREPHTHALATE OLIGOMERS BY GEL PERMEATION CHROMATOGRAPHY SHIONO S Results are described of the spectrometric identification of gpc peaks which had lower molec.wts. Than that of a cyclic trimer and thus had not previously been identified. The presence of a cyclic dimer is reported. 10 refs. Accession no.146152 Item 401 Analytical Chemistry 49, No.12, Dec.1977, p.2349-53 DETERMINATION OF IMIDES, AROMATIC POLYIMIDES, POLYAMIDES, AND POLY(AMIDE-IMIDES) BY ALKALI FUSION REACTION GAS CHROMATOGRAPHY SCHLUETER D D; SIGGIA S

Item 403 Analytical Chemistry 45, No.9, Aug.1973, p.1696-700 CRITERIA OF PRECISION IN QUANTITATIVE ANALYSIS OF EPOXY RESINS AND POLYCAPROLACTONE POLYOLS BY NUCLEAR MAGNETIC RESONANCE HAMMERICH A D; WILLEBOORDSE F G The selectiiive manner in which integrated nmr intensities can be ratioed to yield quantitative information on polymers has been exploited to furnish criteria for precise measurement. The effectiveness of this approach has been demonstrated for epoxy resins and polycaprolactone polyols. The average number of repeat units in these polymers was determined as well as a set of statistical parameters inherent to the choice of ratioing. 10 refs. Accession no.31035

Qualitative and quantitative analysis of imide monomers and imide and amide polymers was carried out by alkali fusion reaction gas chromatography. Samples were hydrolysed with molten potassium hydroxide and the concentrated volatile reaction products separated by gas chromatography. 47 refs. Accession no.115409 Item 402 Polymer 15, No.5, May 1974, p.315-8 GELATION IN THE REACTIONS OF ALIPHATIC DIISOCYANATES WITH TRIOLS HOPKINS W; PETERS R H; STEPTO R F T Gelation in reactions of niax triols with hexamethylene and decamethylene diisocyanates was studied. The gel points occurred at extents of reaction in excess of those predicted by flory-stockmayer theory. The excess intramolecular reaction increased with dilution and with decreases in the molecular weights of the reactants. Kilb’s theory of gelation did not explain the results, but a semiquantitative explanation was found in terms of a combination ofgfrisch’s and kilb’s theories. 17 refs. Accession no.38974

134

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Subject Index

Subject Index A ABS, 73 198 257 324 395 ABSORPTION SPECTRA, 150 184 296 317 321 376 ACCELERATED AGEING, 22 81 128 165 170 ACCELERATED TEST, 22 128 136 144 170 307 ACCELERATOR, 130 186 215 247 311 356 379 ACRYLIC ESTER POLYMER, 28 67 221 ACRYLIC POLYMER, 5 14 16 28 136 331 387 ACTIVATION ENERGY, 9 10 59 69 170 216 242 277 316 397 ADDITIVE, 17 31 43 52 54 70 78 86 103 118 120 146 170 193 197 199 202 210 213 220 230 236 252 254 255 257 258 260 271 294 304 311 321 324 333 338 356 358 371 375 379 ADHESION, 21 47 135 155 207 244 257 296 320 328 ADHESION PROMOTER, 328 ADHESIVE, 11 12 14 16 34 35 57 69 129 146 227 231 244 247 257 261 289 296 325 327 328 381 ADSORPTION, 57 120 257 364 366 ADVANCED COMPOSITE, 317 334 AEROSPACE APPLICATION, 15 52 61 91 317 AGEING, 60 74 111 128 165 168 170 202 214 236 244 251 316 333 347 ALKYD RESIN, 16 44 81 155 277 324 361 ALPHA RELAXATION, 9 56 ALUMINIUM, 11 12 220 227 283 328 AMINE, 6 52 120 210 226 242 252 253 255 258 260 261 282 287 295 298 311 336 356 357 379 382 384 397 AMINO RESIN, 16 AMINO-FORMALDEHYDE RESIN, 162 ANHYDRIDE, 187 260 ANILINE, 242 259 311 397 ANTIDEGRADANT, 54 146 ANTIOXIDANT, 17 170 199 288

AQUEOUS EXTRACT, 167 AQUEOUS SOLUTION, 257 354 ARAMID FIBRE-REINFORCED PLASTIC, 300 301 303 ARGON, 153 359 AROMATIC, 44 124 128 170 226 242 284 298 336 401 AROMATIC AMINE, 34 61 ARRHENIUS’S LAW, 132 196 ARTEFACT, 167 ARTIFICIAL BREAST, 290 346 ARTIFICIAL WEATHERING, 81 ATOMIC ABSORPTION SPECTROSCOPY, 17 272 339 ATOMIC FORCE MICROSCOPY, 77 82 110 244 309 ATTENUATED TOTAL REFLECTION SPECTROSCOPY, 2 28 31 81 89 159 168 200 227 348 355 382 AUGER ELECTRON SPECTROSCOPY, 105 180 207 328 367 AUTOMOTIVE APPLICATION, 15 135 152 200 288

B BANDWIDTH, 128 BENZENE, 130 309 BETA RELAXATION, 224 BINDER, 16 67 103 114 BIOCHEMISTRY, 232 283 BIOCOMPOSITE, 308 BIODEGRADATION, 15 37 BIREFRINGENCE, 2 68 BISMALEIMIDE RESIN, 16 22 163 360 377 BISMALEIMIDO DIPHENYLMETHANE, 36 377 BISPHENOL A, 12 32 126 130 134 148 190 216 243 281 282 311 315 316 322 333 356 357 358 359 384 385 397 BISPHENOL A DICYANATE RESIN, 8 BISPHENOL A DIGLYCIDYL ETHER, 10 56 111 120 124 210 215 258 379 BISPHENOL A POLYCARBONATE, 285 BISPHENOL DIGLYCIDYL ETHER, 10 56 111 120 124

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BISPHENOL S, 256 BLEND, 22 32 53 70 72 84 89 99 101 122 142 151 163 169 193 196 197 202 203 213 214 233 271 285 291 306 320 324 338 BLOWING AGENT, 54 146 230 236 263 294 312 362 BOARD, 247 BORATE, 67 BRILLOUIN SPECTROSCOPY, 71 BUBBLE FORMATION, 215 BUILDING APPLICATION, 15 BUTADIENE-STYRENE COPOLYMER, 73 324 BUTYL ACRYLATE COPOLYMER, 89 191 BUTYLATED HYDROXYTOLUENE, 288 BY-PRODUCT, 148

C CALCIUM CARBONATE, 220 257 CALCIUM STEARATE, 220 CALIBRATION, 53 87 101 172 179 180 184 211 220 236 266 275 311 322 364 CALORIMETRY, 1 3 59 63 190 226 CAR, 152 200 CARBON-13, 99 124 139 145 153 172 173 194 206 218 243 247 360 379 394 397 CARBON BLACK, 54 324 CARBON FIBRE-REINFORCED PLASTIC, 52 120 123 131 188 189 222 223 228 238 240 257 302 308 328 CARBONYL GROUP, 81 128 170 177 269 CARBOXYL GROUP, 44 CARBOXYLIC ACID, 170 CASTOR OIL, 206 209 361 CATALYST, 6 8 39 41 45 97 102 133 146 182 184 194 198 386 391 CELLULAR MATERIAL, 6 16 74 76 94 110 133 146 200 362 375 398 CELLULOSE, 15 75 99 257 CELLULOSE ACETATE, 73 CELLULOSE FIBRE, 15 257

135

Subject Index

CHAIN SCISSION, 48 124 128 285 316 CHEMICAL ANALYSIS, 29 137 147 162 186 256 272 313 339 395 CHEMICAL CLEAVAGE, 81 234 CHEMICAL COMPOSITION, 29 74 78 137 162 342 346 CHEMICAL DEGRADATION, 136 CHEMICAL IONISATION MASS SPECTROSCOPY, 148 CHEMICAL MODIFICATION, 21 52 75 118 149 170 187 198 205 215 225 261 316 355 CHEMICAL PROPERTIES, 15 38 54 136 186 212 314 CHEMICAL RESISTANCE, 38 136 307 390 CHEMICAL STRUCTURE, 3 5 11 14 19 21 25 44 49 51 53 58 60 62 63 64 68 70 78 85 110 113 119 121 128 130 134 139 145 146 148 160 166 169 187 190 194 198 209 216 218 219 247 252 253 284 311 379 382 CHEMILUMINESCENCE, 181 370 CHEMOMETRIC ANALYSIS, 22 141 CHLORINE, 98 147 220 319 CHLOROFLUOROCARBON, 230 236 362 CHLOROFORM, 51 317 CHROMATOGRAPHY, 3 13 17 21 34 45 49 54 63 64 70 74 76 78 86 101 104 113 124 130 134 141 142 143 146 148 156 158 167 174 175 179 181 194 199 201 203 204 209 210 212 219 234 266 297 323 338 358 371 375 377 395 401 CLAY, 102 108 304 COATED FILLER, 257 COATED METAL, 183 307 COATED PIGMENT, 257 COATING, 11 16 20 21 23 24 89 91 103 118 125 126 128 129 137 140 143 144 146 148 150 154 155 156 159 165 183 204 219 272 307 324 329 339 351 352 357 382 390 COBALT NAPHTHENATE, 321 COLUMN CHROMATOGRAPHY, 181 COLUMN PACKING, 179 396 COMPOSITION, 39 46 56 62 101 126 140 168 169 171 285

136

COMPUTER AIDED ANALYSIS, 184 210 220 CONCRETE, 16 CONDENSATION POLYMERISATION, 39 184 194 206 209 266 313 378 397 CONDUCTIVE POLYMER, 26 58 70 CONFOCAL LASER SCANNING MICROSCOPY, 87 CONVERSION, 4 10 11 14 27 28 85 124 157 163 185 206 210 246 285 343 360 387 COPOLYESTER, 218 COPOLYETHERSULFONE, 53 COPOLYMER, 58 151 202 233 245 COPOLYMER COMPOSITION, 218 324 CORE EXCITATION SPECTROSCOPY, 267 268 CORK, 40 COUPLING AGENT, 102 229 329 341 CREEP RATE SPECTROSCOPY, 196 CRESOL-FORMALDEHYDE RESIN, 349 CRESOL-NOVOLAC RESIN, 333 CROSS-POLARISATION, 218 231 360 363 379 394 CROSSLINK, 5 63 64 77 132 140 321 322 343 353 360 377 385 397 399 CROSSLINK DENSITY, 5 77 200 206 264 313 333 386 394 CROSSLINKED, 61 77 121 139 140 145 218 243 246 285 363 CROSSLINKING, 4 10 21 41 48 50 52 58 62 77 90 92 95 99 109 116 117 124 130 138 140 157 166 170 200 202 206 216 218 224 225 229 244 251 283 341 347 377 CROSSLINKING AGENT, 3 110 146 148 170 186 191 360 CRYSTALLINITY, 65 66 68 70 128 169 202 212 324 326 361 CRYSTALLISATION, 68 122 169 212 CRYSTALLOGRAPHY, 82 265 CURE, 1 3 4 63 84 85 132 213 214 226 264 327 334 CURE CYCLE, 217 264 CURE RATE, 46 77 149 252 258 277 281 282 285 313 343 352 CURE TEMPERATURE, 52 99 187 210 226 240 254 255 258

321 334 379 382 385 386 389 397 CURE TIME, 52 187 210 226 254 255 258 298 317 321 379 385 386 CUREMETER, 264 CURING AGENT, 3 6 10 12 31 52 54 59 97 110 117 118 120 123 124 126 133 146 148 163 170 177 186 191 210 215 216 226 227 252 254 255 258 260 264 281 282 284 295 298 303 311 316 321 324 332 333 336 347 356 358 379 384 385 CURING REACTION, 8 10 71 124 140 149 166 215 237 281 282 318 332

D DATA ANALYSIS, 155 178 180 184 197 211 212 DEFECT, 54 144 235 238 DEFORMATION, 163 195 240 303 327 DEGRADATION, 19 20 22 23 60 61 69 70 74 80 81 111 124 125 128 130 136 144 160 165 167 168 170 202 214 215 234 236 250 251 271 292 307 338 DEGRADATION PRODUCT, 20 124 130 168 170 215 236 312 359 DEGREE OF CONVERSION, 10 201 332 DEGREE OF CROSSLINKING, 92 99 200 202 332 DEGREE OF CURE, 42 46 52 119 166 210 226 241 255 258 287 332 354 386 394 DEGREE OF POLYMERISATION, 10 201 245 266 271 276 286 293 297 315 332 378 DENSITY, 66 133 166 200 247 294 DERIVATISATION, 234 256 DERIVATIVE SPECTROSCOPY, 184 DESORPTION, 13 111 DETECTION LIMIT, 34 220 DETERMINATION, 44 96 101 147 158 162 DGEBA, 84 134 DIAMINE, 10 41 56 124 254 258 284 298 385 DIAMINODIPHENYLMETHANE, 216 311 356

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Subject Index

DIAMINODIPHENYLSULFONE, 36 243 254 258 332 384 385 DIBUTYL PHTHALATE, 56 DICUMYL PEROXIDE, 225 DICYANDIAMIDE, 111 296 316 379 DICYANDIAMIDE-EPOXIDE RESIN, 177 DIELECTRIC ANALYSIS, 35 202 251 384 385 389 DIELECTRIC CONSTANT, 155 166 183 226 307 DIELECTRIC LOSS, 111 385 DIELECTRIC PROPERTIES, 41 111 166 183 190 226 246 253 287 307 313 383 389 DIELECTRIC RELAXATION, 10 56 88 384 DIELECTRIC RELAXATION SPECTROSCOPY, 10 56 DIELECTRIC SPECTROSCOPY, 88 111 190 281 DIELECTRIC THERMAL ANALYSIS, 68 DIEPOXIDE, 41 190 DIETHANOLAMINE, 110 DIETHYLENE GLYCOL, 91 249 DIETHYLENE GLYCOL DIMETHYL ETHER, 224 DIETHYLENE TRIAMINE, 12 126 DIFFERENTIAL PHOTOCALORIMETRY, 202 251 352 DIFFERENTIAL THERMAL ANALYSIS, 1 3 10 40 41 52 59 63 66 68 71 95 109 122 149 153 154 157 169 171 185 187 194 202 203 216 217 224 225 251 261 270 271 277 280 313 329 347 353 372 395 DIFFUSE REFLECTANCE SPECTROSCOPY, 79 DIGLYCIDYL ETHER, 12 32 148 190 216 243 311 316 322 356 359 384 385 397 DIGLYCIDYL ETHER BISPHENOL A, 84 134 DIISOCYANATE, 206 209 399 402 DIMETHYL FORMAMIDE, 200 379 396 DINITROPHENYLHYDRAZINE, 162 DIOL, 209 266 356 DIPHENYLMETHANE DIISOCYANATE, 34 42 128 184 200 231 262 267 268

DIPOLE RELAXATION, 226 287 384 DISCOLOURATION, 128 170 DISSOLVING, 285 DISTRIBUTION, 9 44 51 101 110 DOMESTIC APPLIANCE, 74 DOPPLER BROADENING SPECTROSCOPY, 125 DOUBLE BOND, 28 121 145 170 200 390 DYE, 210 255 258 DYNAMIC LIGHT SCATTERING, 275 DYNAMIC MECHANICAL ANALYSIS, 5 9 52 62 85 99 131 202 206 251 261 280 289 310 354 DYNAMIC MECHANICAL PROPERTIES, 83 111 200 253 383 DYNAMIC MECHANICAL SPECTROSCOPY, 163 200 DYNAMIC MECHANICAL THERMAL ANALYSIS, 22 111 177 327 DYNAMIC MODULUS, 9

E ELECTRICAL APPLICATION, 220 ELECTROCHEMICAL DEGRADATION, 307 ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY, 26 37 118 155 183 307 ELECTROCHEMICAL PROPERTIES, 307 365 368 ELECTROCHEMISTRY, 339 365 368 ELECTRON CRYSTALLOGRAPHY, 82 ELECTRON ENERGY LOSS SPECTROSCOPY, 267 268 320 ELECTRON MICROSCOPY, 1 37 68 75 77 81 87 141 268 ELECTRON PARAMAGNETIC RESONANCE SPECTROSCOPY, 20 340 ELECTRON PROBE MICROANALYSIS, 136 ELECTRON SPECTROSCOPY FOR CHEMICAL ANALYSIS, 105 191 355 ELECTRON SPIN RESONANCE SPECTROSCOPY, 20 321 338 340 387

© Copyright 2003 Rapra Technology Limited

ELECTRON TUNNELLING SPECTROSCOPY, 320 ELECTRON-PROBE ANALYSIS, 136 ELECTRONIC APPLICATION, 37 154 249 ELEMENTAL ANALYSIS, 17 54 181 220 225 232 374 ELUTION, 18 45 276 396 ELUTION VOLUME, 34 EMISSION, 6 17 42 150 247 312 EMISSION DECAY, 264 EMISSION SPECTRA, 7 8 42 46 255 258 END GROUP, 42 52 137 245 336 360 END-GROUP ANALYSIS, 134 176 ENERGY DISPERSIVE SPECTROSCOPY, 81 220 ENERGY DISPERSIVE X-RAY ANALYSIS, 346 355 ENGINEERING APPLICATION, 324 327 ENTHALPY, 52 217 239 257 347 EPICHLOROHYDRIN, 315 319 EPICHLOROHYDRIN GLYCIDYL ETHER, 112 EPOXY COPOLYMER, 77 81 124 EPOXY GROUP, 52 59 109 140 311 EPOXY NOVOLAC RESIN, 31 EPOXY PHENOL RESIN, 127 EPOXY RESIN, 4 7 9 10 11 12 16 18 31 32 36 41 43 46 47 52 53 58 61 63 71 80 84 85 88 90 95 98 102 109 111 115 118 120 122 123 124 126 127 130 134 138 140 147 148 149 154 163 168 177 183 186 187 188 189 210 211 215 216 217 220 221 222 226 227 228 229 238 240 241 242 243 249 252 253 254 255 256 257 258 259 260 264 266 280 281 282 284 285 287 295 296 298 300 301 302 303 307 308 311 315 316 317 319 322 325 327 329 331 332 333 334 336 347 351 356 358 359 373 379 383 384 385 391 397 403 EPOXY-AMINE RESIN, 10 56 EQUIPMENT, 70 72 130 178 179 180 181 182 184 212 220 280 298 334 345 380 389 ETHERIFICATION, 52 187 242 379 ETHERSULFONE COPOLYMER, 53 324

137

Subject Index

ETHYL ACETATE, 126 ETHYLENE OXIDE, 96 260 379 EVANESCENT WAVE SPECTROSCOPY, 210 229 255 258 317 EXCITATION, 170 210 220 255 258 EXCITATION SPECTRA, 205 267 268 EXCLUSION CHROMATOGRAPHY, 101 113 156 179 203 225 271 276 338 364 378 396 EXOTHERM, 41 294 EXPOSURE TIME, 128 170 307 EXTRACTION, 13 199 357

F FABRIC REINFORCED, 210 FAILURE, 52 120 123 146 189 240 244 296 328 FAILURE ANALYSIS, 17 52 54 189 FAST ATOM BOMBARDMENT MASS SPECTROSCOPY, 209 FIBRE, 15 17 75 87 120 123 146 213 222 298 350 FIBRE CONCENTRATION, 75 FIBRE CONTENT, 210 FIBRE DIAMETER, 189 258 FIBRE DISTRIBUTION, 189 FIBRE LENGTH, 240 FIBRE OPTIC, 52 184 210 211 252 298 318 334 373 FIBRE ORIENTATION, 87 210 FIBRE-REINFORCED PLASTIC, 15 52 87 120 188 189 222 FIBRE SPACING, 189 222 FIBROUS FILLER, 257 FILLER, 9 17 43 54 87 111 146 150 193 216 220 257 304 324 329 FILM, 2 11 12 23 26 30 140 150 159 170 180 195 205 213 233 244 254 327 368 382 FLAME RETARDANT, 146 220 375 FLOORING, 16 FLUORESCENCE, 8 14 42 46 119 141 210 220 255 258 284 298 324 345 365 370 380 FLUORESCENCE PROBE ANALYSIS, 7 210 FLUORESCENCE SPECTROSCOPY, 7 14 17 42 46 57 119 192 205 210 220 255 258 298 332

138

FLUOROPHORE, 210 255 258 FOAM, 6 16 74 76 94 110 133 146 200 230 236 248 263 268 270 274 290 294 312 324 337 350 362 375 398 FOAMING AGENT, 54 146 FOOD-CONTACT APPLICATION, 17 34 175 357 FORMALDEHYDE, 162 172 219 247 326 FORMALDEHYDE RESIN, 58 FORMULATION, 6 27 94 118 129 226 FORWARD RECOIL SPECTROMETRY, 250 FOURIER TRANSFORM, 128 170 200 210 235 255 283 294 306 317 320 322 324 343 344 345 346 356 359 361 368 370 380 382 388 390 397 FOURIER TRANSFORM INFRARED SPECTROSCOPY, 1 2 4 6 8 14 25 27 28 31 35 36 40 41 42 52 59 67 68 70 72 79 80 81 85 90 95 97 118 124 128 133 138 140 149 153 159 163 165 168 177 185 195 197 205 207 208 215 224 225 232 244 248 259 260 263 274 281 284 285 288 292 296 309 316 318 327 331 337 348 355 FRACTIONATION, 179 201 381 395 FREE RADICAL, 20 144 340 387 FREE RADICAL POLYMERISATION, 3 28 191 321 387 FRUSTRATED MULTIPLE INTERNAL REFLECTION, 337 FUNCTIONAL GROUP, 52 128 267 294 315 FUNCTIONALITY, 194 200 206 209 219 252 257 313 FURAN POLYMER, 26 FURAN RESIN, 16 FURNITURE, 15 375

G GAS ANALYSIS, 213 214 236 GAS CHROMATOGRAPHY, 13 34 64 74 76 86 124 130 137 142 143 158 167 174 175 203 204 209 210 230 232 234 236 249 257 271 272 288 313 339 370 395 398 401 GEL PERMEATION

CHROMATOGRAPHY, 3 17 21 45 63 64 86 134 143 194 201 204 260 272 275 297 335 339 349 381 386 392 393 398 400 GELATION, 62 102 157 206 321 384 399 402 GLASS CONTENT, 210 GLASS FABRIC-REINFORCED, 210 211 GLASS FIBRE, 255 257 GLASS FIBRE-REINFORCED PLASTIC, 135 170 210 258 324 341 GLASS TRANSITION TEMPERATURE, 3 10 52 61 83 88 111 121 145 163 169 177 187 202 212 217 225 243 251 264 280 289 316 327 329 333 351 372 GLASSY, 56 88 190 GLOW DISCHARGE SPECTROSCOPY, 135 GLYCOL, 134 170 344 GRANULE, 220 GRAPHITE, 308 GRAPHITE FIBRE, 298 GRAPHITE FIBREREINFORCED PLASTIC, 280 GRAPHITISATION, 100 GRAVIMETRIC ANALYSIS, 22 36 57 61 63 64 68 69 75 86 109 111 131 149 177 202 GRAVIMETRY, 36 57 61 111 177

H HARDENER, 117 186 215 249 296 HEADSPACE CHROMATOGRAPHY, 175 HEALTH HAZARD, 34 38 143 167 236 262 272 278 290 HEAT AGEING, 131 333 HEAT DEGRADATION, 19 79 124 131 167 215 HEAT RESISTANCE, 34 63 64 69 109 131 149 153 202 215 362 HEAT STABILISER, 257 HEXAFLUOROISOPROPYLIDENE DIPHTHALIC ANHYDRIDE, 116 HEXAMETHYLENE DIISOCYANATE, 116 128 206 278 399 402 HEXANE DIISOCYANATE, 167 HEXANETRIOL, 402 HIGH OSMOTIC PRESSURE CHROMATOGRAPHY, 201

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Subject Index

HIGH PERFORMANCE LIQUID CHROMATOGRAPHY, 49 134 143 148 156 167 204 209 224 256 272 278 293 297 327 339 375 397 HIGH-RESOLUTION ELECTRON LOSS SPECTROSCOPY, 309 HYDROCHLOROFLUOROCARBON, 236 312 HYDROGEN BOND, 31 112 126 128 200 HYDROGEN BONDING, 36 239 263 269 281 282 HYDROGEN BROMIDE, 248 HYDROGEN CHLORIDE, 45 248 HYDROGEN CYANIDE, 248 HYDROLYSIS, 38 98 99 146 177 234 319 HYDROXYL GROUP, 42 44 52 84 206 209 336 379 397 HYDROXYL NUMBER, 4 97 266

I IDENTIFICATION, 70 73 91 130 290 342 346 IMAGING, 70 72 141 146 IMIDE, 357 379 401 IMIDISATION, 205 254 284 343 348 IMMERSION, 22 120 155 307 IMPEDANCE, 56 155 190 287 307 IMPEDANCE SPECTROSCOPY, 226 246 253 287 307 IMPURITY, 260 IN-SITU, 12 27 35 52 120 211 229 242 252 254 258 270 289 298 307 317 334 336 INFRARED SPECTROSCOPY, 1 2 3 6 11 17 22 24 25 27 30 31 36 40 41 42 50 52 59 61 64 67 68 69 70 72 73 79 80 81 82 84 85 86 89 90 92 93 95 97 106 112 118 124 126 128 132 133 138 140 141 142 143 149 153 159 161 163 165 168 172 177 181 184 185 197 198 200 203 204 205 207 208 210 227 232 239 242 244 249 255 256 259 265 269 271 272 274 279 281 282 294 306 311 316 317 320 324 331 336 337 338 339 344 346 350 356 368 370 376 379 382 386 390 391 392 398 INITIATOR, 14 67 113 130 140 195 INSTRUMENTATION, 246 265 380

INTERCALATION, 102 304 INTERFACE, 89 120 123 195 227 240 250 255 257 258 320 382 INTERFACIAL LAYER THICKNESS, 341 INTERFEROMETRY, 196 380 INTERMOLECULAR INTERACTION, 192 285 301 INVERSE GAS CHROMATOGRAPHY, 203 257 271 295 338 351 ION BEAM ANALYSIS, 250 374 IONISATION, 19 148 315 359 IONISATION MASS SPECTROMETRY, 115 ISOCYANATE, 128 133 146 184 200 262 263 294 ISOCYANATE GROUP, 128 206 ISOCYANATE PREPOLYMER, 40 ISOCYANURATE, 94 ISOMER, 34 128 148 224 324 397 ISOPHORONE DIISOCYANATE, 91 ISOPHTHALIC POLYESTER RESIN, 170 ISOTHERMAL, 10 46 52 187 210 254 260 285 321 336 384

K KINETICS, 4 10 14 27 28 35 40 50 59 62 63 70 71 77 84 85 109 122 132 149 168 185 187 196 206 216 263 277 281 282 327 329 347

L LACQUER, 146 249 LAMINATE, 17 72 123 207 LANGIVIN EQUATION, 1 4 5 7 9 10 14 18 23 24 34 36 42 45 49 51 56 57 61 LASER, 255 283 325 345 359 LASER DEGRADATION, 80 LASER INTERFEROMETRY, 196 LASER LIGHT SCATTERING, 32 51 134 297 LASER RAMAN SPECTROSCOPY, 240 380 LEAD, 220 255 LEGISLATION, 34 LIFETIME PREDICTION, 202 LIGHT ABSORPTION, 23 365 LIGHT AGEING, 128 130 144 168 170 LIGHT DEGRADATION, 24 128 130 131 144 168 170

© Copyright 2003 Rapra Technology Limited

LIGHT SCATTERING, 17 54 101 116 157 184 254 258 275 276 297 378 381 LIGHT STABILISER, 170 LIGNIN, 376 LIGNOCELLULOSE, 75 LINSEED OIL, 361 LIQUID CHROMATOGRAPHY, 49 134 142 143 148 156 167 181 203 204 209 219 271 293 338 349 366 375 397 LIQUID COMPOSITE MOULDING, 210 LIQUID CRYSTAL, 72 192 212 324 LITHIUM BROMIDE, 396 LOSS MODULUS, 111 200 261 LOW ENERGY ELECTRON DIFFRACTION, 309

M MAGIC ANGLE, 103 114 218 231 360 379 394 MAGNETIC RESONANCE IMAGING, 66 MALDI-TOF SPECTROSCOPY, 19 94 101 113 115 176 191 MALEIC ANHYDRIDE, 75 218 266 360 MALEIMIDE, 38 MANGANESE OXIDE, 387 MARINE APPLICATION, 307 MASONRY, 103 MASS SPECTROMETRY, 19 21 34 50 76 82 86 91 94 101 113 115 120 124 127 130 135 141 142 148 167 176 181 191 203 209 210 219 232 234 236 245 271 286 293 315 338 359 365 370 395 MATRIX, 9 52 75 120 123 130 175 195 216 285 295 308 327 329 MATRIX-ASSISTED LASER DESORPTION, 19 94 101 113 115 176 191 MDI, 34 42 128 184 200 231 262 267 268 294 MEDICAL APPLICATION, 106 167 346 355 372 MELAMINE, 219 375 382 MELAMINE-FORMALDEHYDE RESIN, 16 25 49 99 136 198 219 247 293 382 MEMBRANE OSMOMETRY, 101 METAL, 11 12 127 183 227 296 METHACRYLOXYPROPYL TRIMETHOXYSILANE

139

Subject Index

COPOLYMER, 341 METHOXYMETHYLMELAMINE RESIN, 293 METHYLIMIDAZOLE, 130 215 MICROANALYSIS, 232 MICROEXTRACTION, 13 MICRO-FTIR SPECTROSCOPY, 195 MICROPROBE, 251 359 MICRORAMAN SPECTROSCOPY, 188 MICROSCOPY, 1 32 54 61 82 87 129 143 169 180 213 265 272 320 323 339 389 MICROSPECTROSCOPY, 72 296 346 MICROSTRUCTURE, 14 17 54 58 100 137 232 323 360 MICROTHERMAL ANALYSIS, 86 MICROWAVE DYNAMIC DIELECTRIC ANALYSIS, 50 MID-INFRARED SPECTROSCOPY, 92 282 MIGRATION, 34 170 346 MINERAL FILLER, 170 220 257 MINERAL WOOL, 16 MODULATED DIFFERENTIAL SCANNING CALORIMETRY, 52 202 217 MODULUS, 10 110 224 313 383 MOISTURE ABSORPTION, 52 99 333 MOISTURE CONTENT, 15 94 114 210 231 280 MOLE RATIO, 145 172 219 MOLECULAR DYNAMICS, 10 56 88 190 198 MOLECULAR INTERACTION, 36 50 120 255 285 MOLECULAR MOBILITY, 56 218 329 377 MOLECULAR ORIENTATION, 2 70 233 MOLECULAR PROBE, 210 212 255 257 MOLECULAR SPECTROSCOPY, 305 MOLECULAR STRUCTURE, 3 5 11 14 19 21 25 29 44 49 51 53 58 60 62 63 64 68 70 74 78 85 110 113 119 121 128 130 134 137 139 145 146 148 160 162 166 169 187 190 194 198 209 216 218 219 227 239 242 243 245 247 252 253 257 266 269 270 271 279 284 285 287 293 309 311 314 316 323 324 331

140

333 335 338 350 361 376 377 379 381 382 391 392 397 401 MOLECULAR WEIGHT, 3 5 17 44 51 54 58 59 62 68 69 78 101 113 116 126 134 148 156 176 201 245 266 271 275 276 286 293 297 315 338 349 358 359 378 381 386 392 MOLECULAR WEIGHT DISTRIBUTION, 51 101 113 134 176 201 MONITORING, 8 14 27 35 37 211 226 229 241 246 252 254 255 262 298 305 316 318 334 373 MONOMER, 40 101 124 167 197 246 293 378 MONTMORILLONITE, 102 108 304 MORPHOLOGICAL PROPERTIES, 9 66 85 94 108 110 169 200 231 261 270 294 318 321 327 329 346 367 MOULD RELEASE AGENT, 135 MULTI-ANGLE LASER LIGHT SCATTERING, 134 276 MULTI-FIBRE, 222 254

N NANOCOMPOSITE, 102 108 NANOFIBRE, 15 NANOFILLER, 108 NATURAL FIBRE, 75 87 NATURAL FIBRE-REINFORCED PLASTIC, 15 257 NEAR-INFRARED SPECTROSCOPY, 22 27 52 84 92 93 141 184 208 229 242 252 253 273 281 282 317 322 324 336 NEODYMIUM, 283 NEUTRON DIFFRACTION, 68 82 83 233 265 320 374 NEUTRON REFLECTION, 309 NEUTRON SCATTERING, 68 82 83 101 233 265 374 NON-DESTRUCTIVE TESTING, 47 235 238 241 314 346 NOVOLAK POLYMER, 31 62 333 349 392 396 NUCLEAR MAGNETIC RESONANCE, 5 17 18 21 33 40 44 47 48 49 50 58 60 62 63 64 66 68 69 82 96 99 103 107 114 117 121 124 139 142 143 145 153 160 171 172 173 181 182 194 199 200 203 204 206 209 218 224 225 231 232 237

241 243 247 256 265 271 272 276 313 314 324 326 330 338 339 360 363 369 379 381 386 393 394 397 403 NUCLEATION, 122 263 NUMBER-AVERAGE MOLECULAR WEIGHT, 44 101

O ODOUR, 17 OLIGOMER, 18 85 126 224 315 321 352 393 397 400 OPTIC FIBRE, 52 133 184 208 210 211 229 252 254 255 258 298 317 318 325 334 373 380 OPTICAL MICROSCOPY, 32 61 153 169 244 380 OPTICAL PROPERTIES, 2 8 14 30 32 42 43 46 53 55 57 119 134 141 150 170 184 210 221 254 255 258 259 274 292 317 326 331 350 367 368 369 380 ORGANOCLAY COMPOUND, 102 108 ORGANOSILOXANE POLYMER, 16 48 ORTHOPHTHALIC POLYESTER RESIN, 170 OSMOMETRY, 17 54 101 134 381 OXIDATION, 24 26 60 61 130 160 161 168 170 207 257 277 OXIRANE, 42 96 260 379

P PACKAGING, 34 37 175 PAINT, 16 81 103 146 278 307 351 361 PARTICLE BOARD, 326 PARTICLE SIZE, 199 291 361 PEAK INTENSITY, 120 184 247 PEEK, 58 169 309 367 PENTAERYTHRITOL, 399 PERFLUOROALKYLETHYL METHACRYLATE COPOLYMER, 191 PERMITTIVITY, 10 56 111 190 383 384 385 PHARMACEUTICAL APPLICATION, 283 372 PHENOL, 158 172 308 349 357 358 PHENOL-EPOXY RESIN, 127 PHENOL-FORMALDEHYDE RESIN, 39 62 69 100 132 162 173 194 349 354 376 381 386

© Copyright 2003 Rapra Technology Limited

Subject Index

392 PHENOL-FORMALDEHYDE RESOL RESIN, 172 PHENOL-NOVOLAC RESIN, 215 333 PHENOLIC COMPOUND, 98 308 PHENOLIC RESIN, 16 100 158 394 PHENYL GLYCIDYL ETHER, 112 242 260 336 397 PHENYLENE DIAMINE, 242 284 397 PHOSPHORESCENCE, 8 264 PHOSPHORUS, 220 PHOTOACOUSTIC SPECTROSCOPY, 24 89 128 170 274 306 320 390 PHOTOCALORIMETRY, 154 202 352 PHOTOCROSSLINKING, 50 140 PHOTODEGRADATION, 20 128 130 144 168 170 PHOTOELECTRON SPECTROSCOPY, 12 82 86 91 105 131 135 180 207 PHOTOINITIATOR, 14 67 140 195 352 PHOTOMETRY, 34 258 PHOTOOXIDATION, 24 130 168 170 PHOTOPOLYMERISATION, 14 21 28 50 67 140 331 PHOTOSENSITISER, 50 PIGMENT, 91 146 150 155 197 220 257 351 PIPE, 230 362 PLANT FIBRE, 75 PLASMA EMISSION SPECTROSCOPY, 272 339 PLASTICISER, 17 54 56 146 197 213 220 POLARISATION, 2 200 226 246 287 363 POLARISED OPTICAL MICROSCOPY, 153 POLYACETYLENE, 64 309 324 POLYACRYLATE, 28 67 221 390 POLYAMIC ACID, 171 205 254 284 304 343 378 POLYARAMIDE, 301 POLYBENZIMIDAZOLE, 73 POLYBISMALEIMIDE, 16 22 163 360 377 POLYCYANATE, 8 41 POLYCYANATE ESTER, 16 POLYDIACRYLATE, 390 POLYDICYANATE, 41 POLYDICYANATE ESTER, 166

POLYDIMETHYL SILOXANE, 13 48 113 244 346 371 POLYDIPHENYLMETHANE DIISOCYANATE, 114 POLYEPICHLOROHYDRIN, 112 225 POLYEPOXIDE, 4 7 9 10 11 12 16 18 31 32 36 41 43 46 47 52 53 58 61 63 71 80 84 85 88 90 95 98 102 109 111 115 118 120 122 123 124 126 127 130 134 138 140 147 148 149 154 163 168 177 183 186 187 188 189 210 211 215 216 217 220 221 222 POLYEPOXYSILOXANE, 59 POLYESTER RESIN, 1 108 170 363 382 POLYESTER-URETHANE, 128 POLYETHER, 58 234 395 POLYETHER POLYOL, 96 263 294 POLYETHER URETHANE, 128 160 161 286 294 POLYETHER-URETHANE, 128 160 161 286 294 POLYETHERIMIDE, 32 73 124 POLYETHYLMETHYLSILOXANE, 101 POLYFURAN, 26 POLYIMIDE, 2 16 30 37 51 58 60 73 79 116 124 131 153 169 171 192 205 207 224 254 284 304 309 324 340 343 348 367 377 378 388 401 POLYISOCYANATE, 231 278 POLYISOCYANURATE, 133 274 318 POLYMALEIMIDE, 38 POLYMER CONCRETE, 16 POLYMERISATION, 3 14 21 26 28 39 42 45 50 56 67 88 92 93 95 101 113 117 128 140 184 185 190 191 206 283 313 321 324 POLYMERISATION CATALYST, 45 184 194 POLYMERISATION INITIATOR, 113 POLYMERISATION KINETICS, 14 28 35 50 70 71 206 306 318 387 393 POLYMERISATION MECHANISM, 14 22 45 95 113 124 331 393 397 POLYMERISATION TEMPERATURE, 28 56 88 206 321

© Copyright 2003 Rapra Technology Limited

POLYMERISATION TIME, 45 184 POLYMETHYL METHACRYLATE, 120 196 201 223 257 275 324 367 POLYMETHYLPHENYLSILOXANE, 149 POLYNADIMIDE, 224 POLYOL, 4 76 97 146 184 200 288 294 362 403 POLYORGANOSILOXANE, 13 16 48 113 POLYPHTHALICDIGLYCOL DIACRYLATE, 67 POLYPYROMELLITIC ACID DIANHYDRIDE, 207 POLYROTAXANE, 239 POLYSILICONE, 16 48 232 314 328 POLYTETRAHYDROFURAN, 19 128 POLYTRIACRYLATE, 390 POLYUREA, 42 110 231 318 324 POLYUREA-URETHANE, 42 94 POLYURETHANE, 6 16 19 20 24 27 33 34 35 40 42 57 58 73 74 76 78 86 89 94 96 97 110 119 125 128 133 144 146 159 161 165 167 184 200 206 209 230 231 234 236 239 244 248 257 263 267 268 269 270 273 274 286 288 290 294 312 318 324 337 350 355 362 375 393 399 POLYURETHANE-ACRYLATE, 195 POLYURETHANE-ROTAXANE, 239 POLYURETHANE-UREA, 42 94 POSITRON ANNIHILATION LIFETIME SPECTROSCOPY, 9 125 144 166 193 333 POST-CURE, 117 POST CURING, 190 215 321 340 POT LIFE, 149 POWDER, 9 150 392 POWDER COATING, 16 148 PRECURSOR, 254 295 378 PREPOLYMER, 35 39 58 128 224 266 358 392 PREPREG, 254 264 298 388 PRESSURE-SENSITIVE ADHESIVE, 69 289 PRINCIPAL COMPONENTS ANALYSIS, 22 184 PRINTING INK, 16 PROBE, 14 46 57 119 184 193 210 211 254 255 257 258 295 334 373

141

Subject Index

PROCESS CONTROL, 52 184 317 PROCESSING, 15 16 150 246 259 270 310 377 PROCESSING AID, 17 54 PROTON MAGNETIC RESONANCE, 153 224 PYRIDINIUM SALT, 210 255 PYROLYSATE, 151 197 PYROLYSIS, 19 79 100 167 174 234 359 PYROLYSIS GAS CHROMATOGRAPHY, 137 142 203 271 338 358 PYROMELLITIC ACID DIANHYDRIDE POLYMER, 207 PYROMELLITIC DIANHYDRIDE, 343

Q QUALITATIVE ANALYSIS, 103 220 342 QUALITY CONTROL, 17 22 92 93 179 184 220 242 262 383 QUANTITATIVE ANALYSIS, 11 44 70 103 173 175 180 220 258 324 QUARTZ, 9 216 254

R RADIATION DEGRADATION, 48 250 RADIATION POLYMERISATION, 390 RADICAL POLYMERISATION, 3 387 RADICAL TRAPPING, 321 RADIOCHEMICAL ANALYSIS, 374 RADIOGRAPHY, 238 299 RAMAN SPECTROSCOPY, 17 49 53 68 70 82 87 89 100 115 123 141 142 170 178 181 188 189 198 203 211 221 222 223 232 240 265 271 279 283 300 302 303 309 320 322 324 325 334 343 368 373 380 388 RAYLEIGH SPECTROSCOPY, 380 REACTION CONDITIONS, 10 39 42 45 56 113 136 218 REACTION INJECTION MOULDING, 27 270 318 REACTION MECHANISM, 8 14 22 42 44 45 58 113 124 130 132 136 166 167 170 206 215 285

142

REACTION PRODUCT, 34 39 98 REACTION RATE, 4 39 85 92 136 149 261 285 REACTION TEMPERATURE, 39 206 REFLECTANCE, 215 254 346 REFLECTANCE SPECTROSCOPY, 168 348 REFLECTION ABSORPTION SPECTROSCOPY, 11 30 REFRACTIVE INDEX, 55 134 210 229 255 258 317 380 REGULATION, 375 REINFORCED PLASTIC, 9 10 15 16 33 52 73 79 82 87 108 120 123 131 135 151 170 188 189 195 197 202 208 210 211 213 214 222 223 228 229 235 237 238 240 254 255 257 258 280 284 299 300 301 302 303 308 310 314 317 320 324 328 329 334 341 373 376 380 388 RELATIVE HUMIDITY, 4 99 307 316 RELAXATION, 66 157 196 347 RELAXATION MAP ANALYSIS SPECTROSCOPY, 202 251 289 RELAXATION TIME, 56 121 157 173 190 218 RESIDUAL MONOMER, 158 184 237 271 324 338 363 RESIDUAL UNSATURATION, 237 RESIN TRANSFER MOULDING, 15 87 208 255 RESOLE RESIN, 39 132 173 194 315 354 386 REVERSE ENGINEERING, 54 REVERSED-PHASE CHROMATOGRAPHY, 256 297 RING OPENING POLYMERISATION, 101 113 ROOM TEMPERATURE, 42 236 310 333 ROOM TEMPERATURE CURING, 227 240 398 ROUND ROBIN TEST, 86 179 RUTHERFORD BACKSCATTERING SPECTROSCOPY, 250

S SALT FOG RESISTANCE, 307 SALT SPRAY TEST, 118 SAMPLING, 70 141 175 234 262 278 280 320

SATURATED POLYESTER, 257 324 395 SCANNING AUGER MICROSCOPY, 180 SCANNING ELECTRON MICROSCOPY, 37 68 75 77 81 87 108 135 307 327 346 SCANNING TUNNELLING MICROSCOPY, 82 87 265 309 SECONDARY ION MASS SPECTROMETRY, 91 120 135 301 309 328 355 SELF-CONDENSATION, 99 382 SENSOR, 35 184 210 254 255 258 307 317 SEQUENCE DISTRIBUTION, 58 139 145 245 SERVICE LIFE, 23 SHELF LIFE, 46 149 SILANE, 64 328 329 SILICA, 9 13 111 216 220 229 SILICA FIBRE, 317 SILICON CARBIDE FIBREREINFORCED PLASTIC, 195 SILICONE POLYMER, 16 48 58 103 232 290 314 328 398 SIZE EXCLUSION CHROMATOGRAPHY, 101 113 156 179 203 225 271 276 338 364 378 396 SMALL ANGLE LIGHT SCATTERING, 68 SMALL ANGLE NEUTRON SCATTERING, 101 233 SMALL ANGLE X-RAY SCATTERING, 110 169 SMART MATERIAL, 317 SMOKE CHAMBER, 248 SOFT SEGMENT, 19 128 200 286 294 SOLID STATE, 107 110 139 145 182 192 200 218 237 243 314 363 379 SOLUBILITY, 64 73 136 153 199 212 224 295 SOLUTION, 72 99 120 126 139 205 243 249 257 258 275 369 378 381 SOLUTION POLYMERISATION, 128 191 399 SOLVENT, 38 51 55 67 126 171 173 200 206 225 249 275 314 343 351 396 SOLVENT EXTRACTION, 230 SPECTRA, 8 22 42 45 101 113 148 151 155 163 166 198 227 243 284 324 SPECTROMETRY, 115 220 228 320 380

© Copyright 2003 Rapra Technology Limited

Subject Index

SPECTROPHOTOMETRY, 38 170 184 380 SPECULAR REFLECTANCE, 284 SPHERULITE, 68 SPIN-LATTICE RELAXATION, 218 STABILISER, 17 170 197 199 220 257 288 STANDARD, 96 98 147 158 175 186 STATIC SECONDARY ION MASS SPECTROMETRY, 82 228 265 286 STATISTICAL PROCESS CONTROL, 184 STERIC EXCLUSION CHROMATOGRAPHY, 266 STRUCTURAL ADHESIVE, 316 325 327 STRUCTURAL PROPERTIES, 132 243 STYRENE, 1 130 145 157 170 321 344 360 363 SUPERCRITICAL FLUID CHROMATOGRAPHY, 104 199 338 371 SURFACE ANALYSIS, 12 17 86 105 120 135 143 180 191 244 250 254 257 265 272 296 320 328 339 355 SURFACE DEFECT, 54 SURFACE ENHANCED RAMAN SCATTERING, 283 SURFACE PROPERTIES, 68 105 131 178 182 191 204 250 257 283 286 309 328 367 368 SURFACE STRUCTURE, 131 244 254 257 286 328 SURFACE TREATMENT, 15 120 123 296 328 SURFACTANT, 146 197 SURGICAL APPLICATION, 160 232 290 372 SWELLING, 15 111 116 155 200 206 313 SYNCHROTRON RADIATION, 82 265 270 294 SYNTHETIC FIBRE, 87 SYNTHETIC FIBREREINFORCED PLASTIC, 300 301 303

T TAN DELTA, 111 163 253 383 TAPPING MODE ATOMIC FORCE MICROSCOPY, 110 TDI, 34 128 200 262

TEMPERATURE MODULATED DIFFERENTIAL SCANNING CALORIMETRY, 10 TEMPERATURE RISING ELUTION FRACTIONATION, 179 TEST EQUIPMENT, 105 106 107 170 186 196 233 273 298 318 TEST METHOD, 34 54 58 73 96 98 104 107 122 123 130 146 147 152 158 167 186 278 302 TEST SPECIMEN, 14 222 236 296 TETRABROMOBISPHENOL A DIGLYCIDYL ETHER, 124 TETRAGLYCIDYL DIAMINODIPHENYL METHANE, 36 TETRAHYDROFURAN, 113 167 396 TETRAHYDROFURAN POLYMER, 19 TETRAMETHYLBIPHENOL, 333 TETRAMETHYLDISILOXANE, 59 TETRAOL, 399 THERMAL ANALYSIS, 17 52 54 68 86 95 142 143 174 202 204 213 214 215 251 271 272 339 372 THERMAL DEGRADATION, 19 69 79 124 131 167 215 230 324 THERMAL GRAVIMETRIC ANALYSIS, 22 63 64 68 69 75 86 109 131 149 202 THERMAL PROPERTIES, 9 32 52 63 83 131 153 163 174 187 190 212 217 225 236 240 243 251 271 280 324 327 333 338 353 370 372 375 THERMAL STABILITY, 34 63 64 69 109 131 149 153 202 215 224 362 THERMOANALYTICAL, 214 THERMODYNAMIC, 122 370 372 THERMOGRAM, 52 187 THERMOGRAVIMETRIC ANALYSIS, 22 63 64 68 69 75 86 109 131 149 153 202 203 225 251 271 292 372 395 THERMOGRAVIMETRY, 215 277 THERMOMECHANICAL ANALYSIS, 131 202 224 251 280 THERMOMECHANICAL PROPERTIES, 112 362 THERMOOXIDATIVE DEGRADATION, 340

© Copyright 2003 Rapra Technology Limited

THIN FILM, 11 12 30 254 296 TIME OF FLIGHT, 19 101 113 120 135 176 191 TIME RESOLVED SPECTROSCOPY, 32 70 270 294 305 TITANIUM, 220 324 328 TITANIUM DIOXIDE, 155 257 351 TITRATION, 18 98 184 230 266 313 TOLUENE DIISOCYANATE, 34 128 200 206 249 262 TOLUENE SULFONYL ISOCYANATE, 97 TOTAL INTERNAL REFLECTION, 345 380 TOXICITY, 38 167 262 278 TRANSMISSION ELECTRON MICROSCOPY, 37 68 75 77 81 87 108 TRANSMISSION SPECTROSCOPY, 27 30 151 320 TRIACRYLATE, 50 TRIMETHYLOL PROPANE, 20 TRIMETHYLSILYL COMPOUND, 234 TRIOL, 209 TWO-DIMENSIONAL, 31 45 58 106 189 198 238 243 306 TWO-PART, 227

U ULTRA-HIGH RESOLUTION SPECTROSCOPY, 196 ULTRASONIC SCANNING, 238 ULTRASONIC SPECTROSCOPY, 235 ULTRASONIC TEST, 313 ULTRAVIOLET CURING, 14 16 28 140 154 ULTRAVIOLET DEGRADATION, 20 128 131 144 ULTRAVIOLET IRRADIATION, 50 125 128 131 144 154 277 ULTRAVIOLET POLYMERISATION, 28 140 ULTRAVIOLET SPECTROSCOPY, 8 17 23 68 126 141 143 170 181 199 204 254 272 309 339 376 ULTRAVIOLET STABILISER, 17 170 UNDERCURING, 237 UNIVERSAL CALIBRATION, 101

143

Subject Index

UNSATURATED POLYESTER, 1 16 44 58 75 108 121 139 145 157 170 185 218 234 237 266 297 321 341 344 363 382 UNSATURATION, 185 UREA, 42 231 267 294 UREA GROUP, 128 200 UREA RESIN, 117 UREA-FORMALDEHYDE RESIN, 117 261 326 URETHANE, 42 249 URETHANE COPOLYMER, 81 URETHANE DIACRYLATE OLIGOMER, 195 URETHANE GROUP, 128 UV VIS SPECTROSCOPY, 8 141 143 170 181

V VAPOUR PHASE OSMOMETRY, 349 VAPOUR PRESSURE OSMOMETRY, 101 134 381 VARNISH, 277 VEHICLE SEAT, 200 VIBRATING NEEDLE CUREMETER, 241 VIBRATIONAL SPECTROSCOPY, 2 6 11 17 24 25 30 36 42 49 52 53 68 70 72 79 82 87 89 90 95 97 100 106 115 123 126 128 132 141 142

144

143 159 161 170 172 178 181 184 189 198 200 203 210 211 222 253 279 320 345 380 VISCOELASTIC PROPERTIES, 60 116 157 200 214 289 316 321 VISCOMETRY, 101 134 323 VISCOSITY, 3 17 21 48 54 69 153 200 258 263 281 282 310 327 383 VISIBLE SPECTROSCOPY, 8 141 143 170 181 272 339 VITRIFICATION, 10 187 217 253 258 294 397 VOLATILE, 124 130 249 359 VOLATILE ORGANIC COMPOUND, 76 312 VOLATILISATION, 236

W WATER, 4 22 31 36 45 57 66 215 294 379 397 WATER ABSORPTION, 15 66 111 155 163 166 177 307 316 333 WATER BLOWN, 263 294 WATER CONTENT, 94 WATER DESORPTION, 111 WATER PIPE, 362 WAVEGUIDE, 229 255 309 345 380 WAVELENGTH, 28 55 170 184 210 220 254 255 258 283

WEATHERING, 23 68 148 165 WIDE ANGLE, 100 233 WIDE ANGLE X-RAY SCATTERING, 65 WLF EQUATION, 9 WOOD, 16 75 231 247 354 WOOD FIBRE-REINFORCED PLASTIC, 15 WOVEN FABRIC, 87

X X-RAY, 82 238 X-RAY ABSORPTION, 220 X-RAY ANALYSIS, 129 204 339 X-RAY CRYSTALLOGRAPHY, 326 X-RAY DIFFRACTION, 68 100 108 122 153 270 272 294 304 361 395 X-RAY FLUORESCENCE SPECTROSCOPY, 17 220 X-RAY PHOTOELECTRON SPECTROSCOPY, 12 82 91 105 131 135 180 207 228 265 301 309 328 367 X-RAY SCATTERING, 65 68 100 108 110 122 153 169 X-RAY SPECTROSCOPY, 12 17 82 91 105 131 135 164 180 207 220 XENON LIGHT, 125 128 XYLENE, 126 249

© Copyright 2003 Rapra Technology Limited

Company Index

Company Index A ABBOTT LABORATORIES, 106 ACADEMIA SINICA, 347 AHMADU BELLO,UNIVERSITY, 261 AIR PRODUCTS & CHEMICALS INC., 133 AKITA,NATIONAL COLLEGE OF TECHNOLOGY, 64 AKRON,UNIVERSITY, 72 114 AKZO ARAMID FIBERS, 301 AKZO NOBEL CHEMICALS INC., 141 AKZO NOBEL COATINGS RESEARCH, 24 AKZO RESEARCH LABORATORIES, 301 ALLIEDSIGNAL INC., 141 236 AMERICAN SOCIETY FOR TESTING & MATERIALS, 96 98 ANNA,UNIVERSITY, 118 APPLIED EXTRUSION TECHNOLOGIES INC., 106 APPLIED SYSTEMS INC., 292 ARCUEIL,CENTRE TECHNIQUE, 124 ARKANSAS,UNIVERSITY, 314 ASI APPLIED SYSTEMS, 25 AT & T BELL LABORATORIES, 348 AVEIRO,UNIVERSIDADE, 40

B BAKELITE-IBERICA, 39 BASF AG, 176 BASF CORP., 262 BAYER AG, 128 337 BAYER CORP., 97 262 BEIJING,INSTITUTE OF AERONAUTICAL MATERIALS, 102 BEIJING,UNIVERSITY OF AERONAUTICS & ASTRONAUTICS, 37 BELARUS ACADEMY OF SCIENCES, 127 BELGRADE,UNIVERSITY, 62 BENDIX CORP., 398 BERLIN,INSTITUTE OF SPECTROCHEMISTRY & APPLIED SPECTROSCOPY, 30

BILLITON RESEARCH BV, 295 BIRMINGHAM,UNIVERSITY, 65 BIRMINGHAM,UNIVERSITY OF ALABAMA, 381 BRITISH AEROSPACE LTD., 217 BRITISH STANDARDS INST., 186 BROOKHAVEN NATIONAL LABORATORY, 125 144 BROOKLYN,POLYTECHNIC UNIVERSITY, 201 213 214 226 252 259 BROOKS AIR FORCE BASE, 278 BUENOS AIRES,COMISION DE INVESTIGACIONES CIENTIFICAS DE LA PROVIN, 9 BUENOS AIRES,UNIVERSITY, 9 BULGARIAN ACADEMY OF SCIENCES, 126 BUNDESMINISTERIUM FUER WIRTSCHAFT, 47

C CALIFORNIA,UNIVERSITY, 309 365 CAMBRIDGE,UNIVERSITY, 233 CAMPEC, 285 CANADA,NATIONAL RESEARCH COUNCIL, 312 CASA, 52 CASE WESTERN RESERVE UNIVERSITY, 70 72 305 CATALUNYA,UNIVERSITAT POLITECNICA, 10 90 CATANIA,UNIVERSITY, 245 CDS ANALYTICAL INC., 174 CENTRE DE RECHERCHES ET D’ETUDES D’ARCUEIL, 266 CENTRE NATIONAL D’EVALUATION DE PHOTOPROTECTION, 170 CHALMERS UNIVERSITY OF TECHNOLOGY, 230 CHANGCHUN,INSTITUTE OF APPLIED CHEMISTRY, 169 CHINESE ACADEMY OF SCIENCES, 102 CIBA SPECIALTY CHEMICALS INC., 148 CIBA-GEIGY COMPOSITES, 327 CINCINNATI,UNIVERSITY, 366 CITY UNIVERSITY,LONDON, 390

© Copyright 2003 Rapra Technology Limited

CLARK ATLANTA UNIVERSITY, 153 CNR, 190 330 CNRS, 206 244 296 CNRS-LEMD, 168 COLOGNE,UNIVERSITY, 197 COLOR, 351 CONICET, 9 CONNECTICUT,UNIVERSITY, 8 42 205 264 284 320 332 CORNELL UNIVERSITY, 250 CRANFIELD,UNIVERSITY, 217 CRAY VALLEY TOTAL, 266 CRETE,UNIVERSITY, 44 CSIC, 14 CYTEC INDUSTRIES INC., 219 293 CZECH RES.INST.FOR SYNTH.RESINS & LACQUERS, 349 CZECHOSLOVAK ACADEMY OF SCIENCES, INST. MACR. CHEM., 379

D DAYTON,UNIVERSITY, 292 DECHEMA, 47 DELAWARE,UNIVERSITY, 107 182 DEUTSCHES KUNSTSTOFFINSTITUT, 315 342 DGA/CENTRE TECHNIQUE D’ARCUEIL, 60 DICKTEN & MASCH MFG.CO., 202 251 DILOR SA, 221 DOW BENELUX NV, 263 DOW CHEMICAL CO., 142 164 262 274 350 368 DOW CHEMICAL USA, 203 267 268 271 318 338 350 DOW CORNING, 113 141 DRESDEN,INSTITUTE OF POLYMER RESEARCH, 30 DSM, 221 DSM MELAMINE, 25 DSM POLYMERS & HYDROCARBONS BV, 360 DSM RESEARCH, 5 29 49 66 92 93 198 306 360 DUPONT AUTOMOTIVE, 179 DUPONT CO., 179 323 DUPONT DE NEMOURS E.I.,& CO.INC., 191 364 366

145

Company Index

DURHAM,UNIVERSITY, 243 DYNORESIN OY, 172 173 194

E EAST CHINA,UNIVERSITY OF SCIENCE & TECHNOLOGY, 269 ECOLE NATIONALE SUPERIEURE DES MINES DE PARIS, 177 316 ECOLE SUPERIEURE DE PHYS.ET CHIM.INDUSTRIELLES, 323 EGYPT,NATIONAL RESEARCH CENTRE, 376 EINDHOVEN,UNIVERSITY OF TECHNOLOGY, 123 189 222 ELASTOGRAN GMBH, 74 ENICHEM, 76 276 ENSAM, 61 EPSRC-DRAL, 270 ESCUELA UNIVERSITARIA DE INGENIERIA TECNICA INDUSTRIAL, 253 ETH-ZENTRUM, 79

GHENT,UNIVERSITY, 286 GIRONA,UNIVERSIDAD, 90 GOMAL,UNIVERSITY, 51 GOODRICH B.F.,CO., 19 GRAN CANARIA,UNIVERSITY, 155

H HANGZHOU,ZHEJIANG UNIVERSITY, 32 HARCOURT BUTLER TECHNOLOGICAL INSTITUTE, 361 HELSINKI,UNIVERSITY, 145 HELWAN,UNIVERSITY, 376 HENKEL CORP., 156 HERCULES INC., 58 HEWLETT-PACKARD CO., 179 HEXCEL COMPOSITES, 52 HONG KONG,CHINESE UNIVERSITY, 51 HONG KONG,UNIVERSITY, 37 HUELS STRUCTURA GMBH, 103 HUNTSMAN CORP., 6

F

I

FAIRFAX,GEORGE MASON UNIVERSITY, 105 180 FENG CHIA,UNIVERSITY, 100 FERRARI, 152 FLORIDA STATE UNIVERSITY, 366 FRANCHECOMTE,UNIVERSITE, 130 FRAUNHOFER-INSTITUT FUER ANG.MATERIALFORSCHUNG, 12 47 FREIBURG,INSTITUT FUER ANALYTISCHE CHEMIE, 103 FRIEDRICH-ALEXANDER UNIVERSITY, 154 FUDAN,UNIVERSITY, 31 FUJI SILYSIA CHEMICAL LTD., 45 FUKUOKA,UNIVERSITY, 235 FUKUSHIMA,NATIONAL COLLEGE OF TECHNOLOGY, 64

IBM ALMADEN RESEARCH CENTER, 378 IBM CORP., 359 ICI, 53 199 262 ICI POLYURETHANES, 114 INDIANA,UNIVERSITY, 340 INDUSTRIAL RESEARCH LTD., 237 INOLEX CHEMICAL CO., 288 INPG, 40 INSA, 27 INSTITUT DE CHIMIE DES SURFACES ET INTERFACES, 135 INSTITUT FUER OBERFLAECHENMODIFIZIERUNG EV, 28 INSTITUT FUER TECHNISCHE UND MAKROMOL.CHEMIE, 215 INSTITUT UNIVERSITAIRE DE RECHERCHE SCIENTIFIQUE, 397 INSTITUTO DE CIENCIA Y TECNOLOGIA DE POLIMEROS, 324 345 380 INTEMA, 75 INTERNATIONAL ORGANIZATION FOR

G GEOCENTERS INC., 367 GEORGIA,INSTITUTE OF TECHNOLOGY, 150 GEORGIA,UNIVERSITY, 318 350

146

STANDARDIZATION, 147 158 IRSID, 296 307 ISRAEL,COLLEGE OF JUDEA AND SAMARIA, 80 ISRAEL,POLICE HQ MATERIALS LABORATORY, 195 ISTITUTO GUIDO DONEGANI SPA, 276 ITALY,NATIONAL RESEARCH COUNCIL, 85 138 163 285 IZASA SA, 220

J JAPAN,CHEMICAL INNOVATION INSTITUTE, 64 JAPAN,HIGH ENERGY ACCELERATOR RESEARCH ORGANISATION, 166 JAPAN,INSTITUTE OF SPACE & ASTRONAUTICAL SCIENCE, 116 JAPAN,NATIONAL LABORATORY FOR HIGH ENERGY PHYSICS, 333 JILIN,UNIVERSITY, 169 JOENSUU,UNIVERSITY, 172 173 194 JOHNS HOPKINS UNIVERSITY, 210 255

K KAHO SINT-LIEVEN, 73 KANSAS STATE UNIVERSITY, 242 336 KASSEL,UNIVERSITAT, 15 KEESLER MEDICAL CENTER, 278 KENTUCKY,UNIVERSITY, 374 KIEV,TARAS SHEVCHENKO UNIVERSITY, 50 KIMBERLY-CLARK CORP., 141 KODAK LTD., 286 KOREA,INSTITUTE OF SCIENCE & TECHNOLOGY, 355 KOREA,RESEARCH INSTITUTE OF CHEMICAL TECHNOLOGY, 84 KUMOH,NATIONAL UNIVERSITY OF TECHNOLOGY, 187 KYOTO,INSTITUTE OF TECHNOLOGY, 341 KYOTO,UNIVERSITY, 83 235 KYUSHU,UNIVERSITY, 235

© Copyright 2003 Rapra Technology Limited

Company Index

L LABORATOIRE DES MATERIAUX PLASTICS ET BIOMATERIAUX, 27 LAWRENCE LIVERMORE NATIONAL LABORATORY, 325 334 373 LEBEDEV,INSTITUTE OF SYNTHETIC RUBBER, 275 LEEDS,UNIVERSITY, 199 351 LEUVEN,CATHOLIC UNIVERSITY, 238 291 LG CHEMICAL LTD., 115 LILLE,UNIVERSITE DES SCIENCES ET TECHNOLOGIES, 101 LIMBURG,UNIVERSITY, 66 LIVERPOOL,UNIVERSITY, 228 LJUBLJANA,BORIS KIDRIC CHEMICAL INSTITUTE, 393 LOCKHEED AEROSPACE CORP., 280 LOUGHBOROUGH, UNIVERSITY, 36 85 392 LOUVAIN,UNIVERSITE CATHOLIQUE, 53

M MADRID,UNIVERSIDAD CARLOS III, 14 MALAYSIA,SCIENCE UNIVERSITY, 140 MANCHESTER,MATERIALS SCIENCE CENTRE, 240 MANCHESTER, METROPOLITAN UNIVERSITY, 50 MANCHESTER,UNIVERSITY, 189 222 223 240 300 MAR DEL PLATA,UNIVERSIDAD NACIONAL, 39 77 MARLIN SCIENTIFIC LTD., 352 MARQUETTE,UNIVERSITY, 292 MARYLAND,UNIVERSITY, 181 MASSACHUSETTS INSTITUTE OF TECHNOLOGY, 377 389 MASSACHUSETTS, UNIVERSITY, 94 MAX-PLANCK-INSTITUT FUER POLYMERFORSCHUNG, 101 176 MCLAREN, 152 MCMASTER UNIVERSITY, 164 190 267 268 384 385 MEDTRONIC INC., 161

MERSEBURG,INSTITUTE OF EXPERIMENTAL PHYSICS, 311 MERSEBURG,TECHNISCHE HOCHSCHULE, 356 MERSEBURG,UNIVERSITY, 379 MICHELIN, 152 MICHIGAN,UNIVERSITY, 262 279 304 MISSISSIPPI,STATE UNIVERSITY, 212 381 MISSOURI-KANSAS CITY,UNIVERSITY, 20 125 144 MISSOURIROLLA,UNIVERSITY, 95 MITSUBISHI ELECTRIC CORP., 3 MITSUBISHI PETROCHEMICAL CO.LTD., 358 MITSUI CHEMICALS INC., 64 MITSUI TOATSU CHEMICALS INC., 200 207 MONASH,UNIVERSITY, 193 317 MONSANTO CO., 141 MONTREAL,ECOLE POLYTECHNIQUE, 257 MOSCICKI I.,INDUSTRIAL CHEMISTRY RES.INST., 162

N NAGOYA,INSTITUTE OF TECHNOLOGY, 45 NAGOYA,UNIVERSITY, 358 NANJING,UNIVERSITY, 26 37 NANTES,UNITE DE SENSOMETRIE ET DE CHIMIOMETRIE, 27 NAPLES,INSTITUTE OF RESEARCH & TECHNOLOGY OF PLASTICS MATERIALS, 36 NAPOLI,UNIVERSITA, 132 226 253 281 287 NASA LANGLEY RESEARCH CENTER, 131 NEBRASKA,UNIVERSITY, 260 NESTE CHEMICALS R & T, 145 NESTE GROUP, 145 NESTE OY TECHNOLOGY CENTRE, 117 NEW MEXICO,STATE UNIVERSITY, 308 370 NEW SOUTH WALES,UNIVERSITY, 137 234 NEW YORK,POLYTECHNIC

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UNIVERSITY, 246 253 281 282 287 NEWCASTLE UPON TYNE,UNIVERSITY, 68 NEWCASTLE,UNIVERSITY OF NORTHUMBRIA, 199 NIPPON BIO-RAD LABORATORIES, 331 NIRSYSTEMS INC., 184 273 NIST,POLYMERS DIV., 108 NITTO BOSEKI CO.LTD., 341 NORTH CAROLINA,STATE UNIVERSITY, 164 NORTH DAKOTA STATE UNIVERSITY, 4 23 89 159 382 NORTHUMBRIA,UNIVERSITY, 68 NORTHWESTERN UNIVERSITY, 7 NOTTINGHAM,UNIVERSITY, 55 286

O OFITECH SA, 99 OHIO,STATE UNIVERSITY, 1 321 ONERA, 61 ONTARIO,MINISTRY OF THE ENVIRONMENT, 370 OSAKA MUNICIPAL INDUSTRIAL RESEARCH INSTITUTE, 341 OSAKA MUNICIPAL TECHNICAL RESEARCH INSTITUTE, 396

P PACIFIC NORTHWEST NATIONAL LABORATORY, 141 PAIS VASCO,UNIVERSIDAD, 39 77 128 185 PAU,UNIVERSITE, 224 PAUL SABATIER,UNIVERSITE, 329 PAUL-SCHERRER-INSTITUT, 79 PENNSYLVANIA,STATE UNIVERSITY, 178 239 PERKIN-ELMER CORP., 280 PERSTORP ANALYTICAL, 184 PERUGIA,UNIVERSITY, 71 185 252 PETRU PONI,INSTITUTE OF MACROMOLECULAR CHEMISTRY, 69 PILKINGTON TECHNOLOGY

147

Company Index

CENTRE, 56 88 PLYMOUTH,UNIVERSITY, 241 POHANG,UNIVERSITY OF SCIENCE & TECHNOLOGY, 171 POLISH ACADEMY OF SCIENCES, 139 218 363 POLYMER LABORATORIES, 383 POLYTRIS LTD., 80 PORSCHE, 152 PROCTER & GAMBLE CO., 45 104 141 331 371 PSA ETUDES ET RECHERCHES CENTRE TECHNIQUE DE BELCHAMP, 135

Q QUEEN MARY & WESTFIELD COLLEGE, 123 QUEENSLAND,UNIVERSITY, 48 387

R RAPRA TECHNOLOGY LTD., 16 17 54 78 146 248 313 391 RENSSELAER POLYTECHNIC INSTITUTE, 95 188 RIO DE JANEIRO,CIDADE UNIVERSITARIA, 33 RIO DE JANEIRO,UNIVERSIDADE FEDERAL, 18 RIO GRANDE DO SUL,UNIVERSIDADE FEDERAL, 71 216 ROCKWELL INTERNATIONAL CORP., 310 ROUEN,UNIVERSITY, 99 277 RUSSIAN ACADEMY OF SCIENCES, 196 RUTGERS,UNIVERSITY, 106

S SAARLANDES,UNIVERSITAT, 11 SALFORD,UNIVERSITY, 295 SAPICI SPA, 34 SARDAR PATEL UNIVERSITY, 109 SCHNEIDER ELECTRIC, 168 SEOKYEONG,UNIVERSITY, 115 SEOUL,NATIONAL UNIVERSITY, 355 SERVICE CENTRAL D’ANALYSE, 209

148

SHEFFIELD,HALLAM UNIVERSITY, 82 265 SHELL LOUVAIN-LA-NEUVE, 362 SHENYANG,AGRICULTURAL UNIVERSITY, 37 SHIMADZU EUROPE GMBH, 315 SINGAPORE,INSTITUTE OF MATERIALS RESEARCH & ENGINEERING, 59 SINGAPORE,NATIONAL UNIVERSITY, 59 SMITH & NEPHEW GROUP RESEARCH LTD., 167 SOFIA,UNIVERSITY OF CHEMICAL TECHNOLOGY & METALLURGY, 112 126 SOLOMAT TA INSTRUMENTATION, 289 SOUTH CAROLINA,UNIVERSITY, 211 322 334 SOUTH DAKOTA,SCHOOL OF MINES & TECHNOLOGY, 229 SOUTHAMPTON,UNIVERSITY, 283 SOUTHERN COMPANY SERVICES, 150 SOUTHERN ILLINOIS,UNIVERSITY, 210 SOUTHWEST TEXAS,STATE UNIVERSITY, 278 ST.THOMAS,UNIVERSITY, 160 STRATHCLYDE,UNIVERSITY, 68 111 SUMITOMO CHEMICAL CO.LTD., 166 333 SURREY,UNIVERSITY, 22 120 328 SVISTOV,D.TSENOV ECONOMIC UNIVERSITY, 112 SWANSEA,UNIVERSITY OF WALES, 88 SYNPO, 134 256 297 SYRACUSE,UNIVERSITY, 149

T TAIWAN,NATIONAL CHIAO TUNG UNIVERSITY, 122 TAIWAN,NATIONAL KAOHSIUNG UNIVERSITY OF APPLIED SCIENCE, 41 TAIWAN,NATIONAL TSING HUA UNIVERSITY, 157

TAIWAN,YUAN-ZE UNIVERSITY, 157 TAMPERE,UNIVERSITY OF TECHNOLOGY, 46 57 119 TARRAGONA,UNIVERSITAT ROVIRA I VIRGILI, 225 TEL AVIV,UNIVERSITY, 80 TEMPLE UNIVERSITY, 343 388 TEXAS,A & M UNIVERSITY, 369 TIMISOARA,WEST UNIVERSITY, 13 TOKAI,TECHNICAL CENTER FOUNDATION, 45 TOKYO,INSTITUTE OF TECHNOLOGY, 2 63 TOKYO,UNIVERSITY, 43 116 192 333 TOLEDO,UNIVERSITY, 372 TORONTO,UNIVERSITY, 232 TOULON,UNIVERSITY, 81 TOYOTA CENTRAL R & D LABORATORIES INC., 136 TOYOTA MOTOR CORP., 136 TSINGHUA,UNIVERSITY, 67 TSUKUBA, ELECTROTECHNICAL LABORATORY, 125 TSUKUBA,UNIVERSITY, 144 TUFTS UNIVERSITY, 254 258 298

U UDC, 91 UFZ UMWELTFORSCHUNGSZENTRUM LEIPZIG-HALLE GMBH, 215 UK,DEFENCE EVALUATION & RESEARCH AGENCY, 22 UK,DEFENCE RESEARCH AGENCY, 243 UK,LABORATORY OF THE GOVERNMENT CHEMIST, 375 UK,NATIONAL PHYSICAL LABORATORY, 353 UKRAINE,NATIONAL ACADEMY OF SCIENCES, 50 UMIST, 123 189 222 240 263 270 294 300 302 303 UNITED AIRLINES, 299 US,AIR FORCE ACADEMY, 278 US,ARMED FORCES INSTITUTE OF PATHOLOGY, 290 346 US,ARMY RESEARCH LABORATORY, 165

© Copyright 2003 Rapra Technology Limited

Company Index

US,DEPT.OF AGRICULTURE, 366 US,DEPT.OF AGRICULTURE,FOREST PRODUCTS LABORATORY, 354 US,FOOD & DRUG ADMINISTRATION, 290 US,NATIONAL INSTITUTE FOR OCCUPA.SAFETY & HEALTH, 278 US,NATIONAL INSTITUTE OF STANDARDS & TECHNOLOGY, 108 208 210 211 255 US,NATIONAL INSTITUTES OF HEALTH, 72 268 US,NAVAL AIR DEVELOPMENT CENTER, 377 US,NAVAL RESEARCH LABORATORY, 180 367 US,OCCUPATIONAL SAFETY & HEALTH ADMINISTRATION, 278 UTRECHT,UNIVERSITY, 301

V VIENNA,TECHNICAL UNIVERSITY, 148 VIETNAM,CENTRE DE SERVICE D’ANALYSE ET D’EXPERIMENTATION, 206 209 VILLANOVA,UNIVERSITY, 366 VIRGINIA,POLYTECHNIC INSTITUTE & STATE UNIVERSITY, 35 110 231 239

W WALES,UNIVERSITY, 56 WARSAW,DEPT.OF ANALYSIS & CHARACT.OF PLAST., 335 WARSAW,INDUSTRIAL CHEMISTRY RESEARCH INSTITUTE, 357 WARWICK,UNIVERSITY, 21 113 WASHINGTON G.,UNIVERSITY, 105 WASHINGTON STATE,UNIVERSITY, 370 WASHINGTON,UNIVERSITY, 141

© Copyright 2003 Rapra Technology Limited

WATERLOO,UNIVERSITY, 386 WEIZMANN INSTITUTE OF SCIENCE, 195 WESTINGHOUSE SAVANNAH RIVER CO., 141 WIGGINS TEAPE LTD., 390 WILLIAM & MARY COLLEGE, 35 WILLIAMSBURG,COLLEGE OF WILLIAM & MARY, 131 WISCONSINMADISON,UNIVERSITY, 354 WITCO CORP., 143 204 272 339 WITWATERSRAND, UNIVERSITY, 247 326 344 WRIGHT-PATTERSON AIR FORCE BASE, 91

Y YAMAGATA,UNIVERSITY, 63 YUAN ZE,INSTITUTE OF TECHNOLOGY, 227

Z ZHEJIANG,UNIVERSITY, 102

149

Company Index

150

© Copyright 2003 Rapra Technology Limited

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