Cycloaddition reactions have been employed in polymer synthesis since the mid-nineteen sixties. This critical review will highlight recent notable advances in this field. For example, [2 + 2] cycloaddition reactions have been utilized in numerous polymerizations to enable the construction of strained polymer systems such as poly(2-azetidinone)s that can, in turn, afford polyfunctional beta-amino acid derived polymers. Polymers have also been synthesized successfully via (3 + 2) cycloaddition methods utilizing both thermal and high-pressure conditions. 'Click chemistry'--a process involving the reaction of azides with olefins, has also been adopted to generate linear and hyperbranched polymer architectures in a very efficient manner. [4 + 2] Cycloadditions have also been utilized under thermal and high-pressure conditions to produce rigid polymers such as polyimides and polyphenylenes. These cycloaddition polymerization methods afford polymers with potential for use in high performance polymers applications such as high temperature resistant coatings and polymeric organic light emitting diodes.

It has been found that hydrogels may be formed by microwave irradiation of aqueous solutions containing appropriate combinations of polymers. This new method of hydrogel synthesis yields sterile hydrogels without the use of monomers, eliminating the need for the removal of unreacted species from the final product. Results for two particularly successful combinations, poly(vinyl alcohol) with either poly(acrylic acid) or poly(methylvinylether-alt-maleic anhydride), are presented. Irradiation using temperatures of 100-150 °C was found to yield hydrogels with large equilibrium swelling degrees of 500-1000 g g(-1) . Material leached from both types of hydrogel shows little cytotoxicity towards HT29 cells.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

No abstract

Modern polyesters: chemistry and technology of polyesters and copolyesters Wiley, 2003 784 pp; price £180 ISBN 0-471-49856-4 The progression of polyester technology and the diverse applications of these polymers is described in this book and reinforces the synopsis of this title: 'polyesters are ubiquitous materials in modern life'. Indeed, the wide range of applications of polyesters and their associated copolymers is detailed within this well-written book and includes utilization of polyesters in coatings, glass-fibrereinforced polyesters, which were first employed during the Second World War, films and 'tuneable' fibres that exhibit strengths and flexibilities comparable to nylon. Further coverage is provided that outlines the use of polyesters as recyclable bulk materials in injection moulding, and as fibres with applications in textiles and as surgical absorbable sutures.The book is divided into seven main sections (Historical Overview, Polymerisation and Polycondensation, Types of Polyester, Fibres and Compounds, Depolymerisation and Degradation, Liquid Crystal Polyesters and Unsaturated Polyesters), each comprising several chapters written by experts in the fields. The chapters are comprehensive in nature and provide practical guides for polyester synthesis/processing. Furthermore, each chapter has an excellent bibliographic subsection, thereby rendering this title an excellent starting point for key literature and patent references for chemists embarking on projects in the polyester chemistries. The book begins with a historical overview of polyesters and their related copolymers, and describes the first commercially important class of polyesters that were derived initially from phthalic anhydride and glycerol. The seminal work of Carothers and coworkers in 1928 on aromatic polyesters derived from the polycondensation of dicarboxylic acids with dihydroxy alcohols also receives appropriate coverage, which reflects the key role that poly(ethylene terephthalate) has in a wide range of modern applications. Other key developments, such as polycarbonates formed from aromatic diols and a carbonic acid source, are also highlighted. The wide variety of monomers and catalysts that have been used to date are discussed, although limited mechanistic detail of the catalysed polymerization processes has been described. This omission, however, does not detract from the substantial body of information on polyester chemistries, which is of interest to the academic and industrial sectors alike. There is an interesting economic discussion on the infrastructure needed for recycling of polyesters and the potential financial impact of such an undertaking.The book was informative from the outset, with excellent provision of highquality figures, schemes and tables. The editors have ensured that the text is written clearly in a consistent style and supplemented with a comprehensive set of references to enable the reader, if he/she so desires, to research the subject in more detail. In summary, this book should be a key acquis...