Polymer Degradation and Stabilization

Polymer Degradation and Stabilization
Author: W. L. Hawkins
Publisher: Springer Science & Business Media
Total Pages: 129
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 3642693768

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.

Thermal Degradation of Polymeric Materials

Thermal Degradation of Polymeric Materials
Author: Krzysztof Pielichowski
Publisher: iSmithers Rapra Publishing
Total Pages: 324
Release: 2005
Genre: Science
ISBN: 9781859574980

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.

Polymer Degradation and Stabilisation

Polymer Degradation and Stabilisation
Author: Norman Grassie
Publisher: CUP Archive
Total Pages: 236
Release: 1988-04-14
Genre: Science
ISBN: 9780521357975

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.

Developments in Polymer Characterisation—1

Developments in Polymer Characterisation—1
Author: J. V. Dawkins
Publisher: Springer Science & Business Media
Total Pages: 287
Release: 2012-12-06
Genre: Science
ISBN: 9400996462

Over two decades ago, !he term characterisation covered just those techniques which measured the properties of polymers in solution in order to determine molecular weight and size. The discoveries of stereoregular polymers and polymer crystals created the need for new and advanced techniques for characterising chain structures and bulk properties. Further demands for new and improved characterisation methods for bulk polymers have resulted from the recent development and exploitation of multi phase polymeric systems, such as polymer blends, block and graft copolymers, and polymer composites. Today, therefore, characterisation is a very important part of polymer science. The polymer chemist must know the chain length, chain microstructure and chain conformation of the polymers he or she has prepared, i. e. the determination of molecular properties. The scientist involved in exploiting polymers in such applications as plastics, elastomers, fibres, surface coatings and adhesives must be informed on the morphology and physical and mechanical behaviour of his or her products, i. e. the determination of bulk and surface properties and their dependence on molecular properties. The techniques required for these determinations now cover an extremely wide field. Our aim has been to review a number of techniques critically and in sufficient depth so that the present state and future potential of each technique may be judged by the reader. Three criteria were used in the selection of techniques. First, we wished to present new methods which have been developed actively in the polymer field during the past five years.

Mechanisms of Polymer Degradation and Stabilisation

Mechanisms of Polymer Degradation and Stabilisation
Author: G. Scott
Publisher: Springer Science & Business Media
Total Pages: 336
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 9401138389

The purpose of this publication is two-fold. In the first place it is intended to review progress in the development of practical stabilising systems for a wide range of polymers and applications. A complemen tary and ultimately more important objective is to accommodate these practical developments within the framework of antioxidant theory, since there can be little question that further major advances in the practice of stabilisation technology will only be possible on a firm mechanistic foundation. With the continual increase in the number of commercial anti oxidants and stabilisers, often functioning by mechanisms not even considered ten years ago, there is a need for a general theory which will allow the potential user to predict the performance of a particular antioxidant structure under specific practical conditions. Any such predictive tool must involve a simplified kinetic approach to inhibited oxidation and, in Chapter 1, Denisov outlines a possible mechanistic approach with the potential to predict the most useful antioxidant to use and the limits of its usefulness. In Chapter 2, Schwetlick reviews the current state of knowledge on the antioxidant mechanisms of the phosphite esters with particular emphasis on their catalytic peroxidolytic activity. Dithiophosphate v vi PREFACE derivatives show a similar behaviour but for quite different reasons and, in Chapter 3, AI-Malaika reviews information available from analytical studies, particularly using 31p_NMR spectroscopy, to elucid ate the complex chemistry that leads to the formation of the antioxidant -active agents.

Developments in Polymer Stabilisation—8

Developments in Polymer Stabilisation—8
Author: G. Scott
Publisher: Springer Science & Business Media
Total Pages: 303
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 9400934297

The purpose of the present series of publications is two-fold. In the first place it is intended to review progress in the development of practical stabilising systems for a wide range of polymers and applications. A complementary and ultimately more important objec tive is to accommodate these practical developments within the framework of antioxidant theory, since there can be little question that further major advances in the practice of stabilisation technology will only be possible on the basis of a firm mechanistic foundation. Research into the role of 'stable' free radicals as antioxidants and stabilisers for polymers has intensified in recent years. Nitroxyl radicals (nitroxides) were the earliest long-lived radicals to be investi gated in detail and Maslov and Zaikov review the developments that have taken place in understanding their reaction mechanisms from the time when they were first investigated in liquid hydrocarbon systems to the present day when their outstanding performance as light stabilisers has been the object of much scientific research. Although some features of their reactivity remain obscure, the authors approach the problem kinetically and indicate the factors limiting their effectiveness.

Fundamentals of Polymer Degradation and Stabilization

Fundamentals of Polymer Degradation and Stabilization
Author: N.S. Allen
Publisher: Springer Science & Business Media
Total Pages: 218
Release: 1992-10-31
Genre: Technology & Engineering
ISBN: 9781851667734

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.

Developments in Polymer Degradation—7

Developments in Polymer Degradation—7
Author: N. Grassie
Publisher: Springer Science & Business Media
Total Pages: 282
Release: 2012-12-06
Genre: Science
ISBN: 9400934254

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.

Biodegradable polymers for industrial applications

Biodegradable polymers for industrial applications
Author: Ray Smith
Publisher: CRC Press
Total Pages: 556
Release: 2005-05-17
Genre: Technology & Engineering
ISBN: 9780849334665

The vast majority of plastic products are made from petroleum-based synthetic polymers that do not degrade in a landfill or in a compost-like environment. Therefore, the disposal of these products poses a serious environmental problem. An environmentally-conscious alternative is to design/synthesize polymers that are biodegradable. Biodegradable polymers for industrial applications introduces the subject in part one by outlining the classification and development of biodegradable polymers with individual chapters on polyhydroxyalkanoates, polyesteramides and thermoplastic starch biodegradable polymers and others. The second part explores the materials available for the production of biodegradable polymers. Polymers derived from sugars, natural fibres, renewable forest resources, poly(lactic acid) and protein-nanoparticle composites will be looked at in detail in this section. Part three looks at the properties and mechanisms of degradation, prefacing the subject with a chapter on current standards. The final part explores opportunities for industrial applications, with chapters on packing, agriculture and biodegradable polycaprolactone foams in supercritical carbon dioxide. Biodegradable polymers for industrial applications explores the fundamental concepts concerning the development of biodegradable polymers, degradable polymers from sustainable sources, degradation and properties and industrial applications. It is an authoritative book that will be invaluable for academics, researchers and policy makers in the industry.