The purpose of this volume, like that of its predecessors in the series, is to present a selection of topics which are representative of the continually expanding area of polymer degradation. It will be obvious that some of these topics emanate from academic studies, others from more applied backgrounds, but it is anticipated that all will be seen to be of vital relevance to one or other of the currently advancing fields of polymer technology. The first two chapters deal with specific classes of polymers, and particularly with their mechanisms and products of thermal degrada tion. Thus in Chapter 1 Dr McNeill discusses the reactions of the ammonium, alkali and alkaline earth metal salts of poly(methacrylic acid) and their copolymers with methyl methacrylate. These water soluble 'ionomers' have valuable technological applications. In Chap ter 2 Professor Montaudo and Dr Puglisi perform a valuable service by drawing together and critically reviewing, for the first time to my knowledge, the mechanisms of thermal degradation of the various classes of condensation polymers which are of industrial significance. This includes, for example, the polyurethanes, polyureas, polyesters, polycarbonates, polyamides, polyimides, polyethers, polysulphides, polysulphones, polyschiff bases, polysiloxanes and polyphosphazenes.

The study of polymer degradation and stabilisation is of considerable practical importance as the industrial uses of polymeric materials continue to expand. In this book, the authors lucidly relate technological phenomena to the chemistry and physics of degradation and stabilisation processes. Degradation embraces a variety of technologically important phenomena ranging from relatively low temperature processes such as 'weathering' of plastics, 'fatigue' of rubbers through the processing of polymers in shearing mixers to very high temperature processes such as flammability and ablation. All these technological phenomena have in common certain basic chemical reactions. Thus 'weathering' has its roots in photo-oxidation, 'fatigue' and melt-degradation in mechano-oxidation and flammability, and ablation in ablation in pyrolysis and vapour phase oxidation.

The development of polymers as an important class of material was inhibited at the first by the premature failure of these versatile compounds in many applications. The deterioration of important properties of both natural and synthetic polymers is the result of irreversible changes in composition and structure of polymers molecules. As a result of these reactions, mechanical, electrical and/or aesthetic properties are degraded beyond acceptable limits. It is now generally recognized that stabilization against degradation is necessary if the useful life of polymers is to be extended sufficiently to meet design requirements for long-term applications. Polymers degrade by a wide variety of mechanisms, several of which affect all polymers through to varying degree. This monograph will concentrate on those degradation mechanisms which result from reactions of polymers with oxygen in its various forms and which are accelerated by heat and/or radiation. Those stabilization mechanisms are discussed which are based on an understanding of degradation reaction mechanisms that are reasonably well established. The stabilization of polymers is still undergoing a transition from an art to a science as mechanisms of degradation become more fully developed. A scientific approach to stabilization can only be approached when there is an understanding of the reactions that lead to degradation. Stabilization against biodegradation and burning will not be discussed since there is not a clear understanding of how polymers degrade under these conditions.

During the past decade, the field of polymer degradation and stabilization has become a subject of central importance in polymer science and technology. This book provides a fundamental source of information designed for those with only a basic understanding of the background of the field.

Understanding the thermal degradation of polymers is of paramount importance for developing a rational technology of polymer processing and higher-temperature applications. Controlling degradation requires understanding of many different phenomena, including chemical mechanisms, the influence of polymer morphology, the complexities of oxidation chemistry, and the effects of stabilisers, fillers and other additives. This book offers a wealth of information for polymer researchers and processors requiring an understanding of the implications of thermal degradation on material and product performance.

Understanding the dynamics of reactive polymer processes allows scientists to create new, high-value, high-performance polymers. This book is an indispensable resource for researchers and practitioners working in this area. It includes coverage of thermoplastics, thermoset and reactive polymers, together with practical industrial processes and modern chemorheological models and tools.

Presenting practical information on new and conventional polymers and products as alternative materials and end-use applications, this work details technological advancements in high-structure plastics and elastomers, functionalized materials, and their product applications. The book also provides a comparison of manufacturing and processing techniques from around the world. It emphasizes product characterization, performance attributes and structural properties.