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.

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.

Biodegradable Plastics and Polymers

Biodegradable Plastics and Polymers
Author: Y. Doi
Publisher: Elsevier
Total Pages: 646
Release: 2013-10-22
Genre: Technology & Engineering
ISBN: 1483290409

In the past 25 years, plastic products have gained universal use not only in food, clothing and shelter, but also in the transportation, construction, medical and leisure industries. Whereas previously synthetic plastics were developed as durable substitute products, increasing concern for the global environment and solid waste management has resulted in an urgent demand for biodegradable plastics. The main topics of the Third International Scientific Workshop were as follows: 1. Biodegradation of polymers and plastics 2. Environmental degradation of plastics 3. Synthesis and properties of new biodegradable plastic materials 4. Biodegradation and morphologies of polymer blends 5. Development of biodegradation test methods 6. Governmental policy, regulation and standards.

Chemorheology of Polymers

Chemorheology of Polymers
Author: Peter J. Halley
Publisher: Cambridge University Press
Total Pages: 445
Release: 2009-05-28
Genre: Science
ISBN: 0521807190

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.

Handbook of Engineering Polymeric Materials

Handbook of Engineering Polymeric Materials
Author: P. Cheremisinoff
Publisher: CRC Press
Total Pages: 928
Release: 1997-07-25
Genre: Technology & Engineering
ISBN: 9780824797997

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.

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.

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.

Degradable Polymers

Degradable Polymers
Author: G. Scott
Publisher: Springer Science & Business Media
Total Pages: 284
Release: 2012-12-06
Genre: Technology & Engineering
ISBN: 9401105715

Few scientific developments in recent years have captured the popular imagination like the subject of'biodegradable' plastics. The reasons for this are complex and lie deep in the human subconscious. Discarded plastics are an intrusion on the sea shore and in the countryside. The fact that nature's litter abounds in the sea and on land is acceptable because it is biodegradable - even though it may take many years to be bioassimilated into the ecosystem. Plastics litter is not seen to be biodegradable and is aesthetically unacceptable because it does not blend into the natural environment. To the environmentally aware but often scientifically naive, biodegradation is seen to be the ecologically acceptable solution to the problem of plastic packaging waste and litter and some packaging manufacturers have exploited the 'green' consumer with exaggerated claims to 'environmentally friendly' biodegradable packaging materials. The principles underlying environmental degradation are not understood even by some manufacturers of 'biodegradable' materials and the claims made for them have been categorized as 'deceptive' by USA legislative authorities. This has set back the acceptance of plastics with controlled biodegradability as part of the overall waste and litter control strategy. At the opposite end of the commercial spectrum, the polymer manufactur ing industries, through their trade associations, have been at pains to discount the role of degradable materials in waste and litter management. This negative campaign has concentrated on the supposed incompatibility of degradable plastics with aspects of waste management strategy, notably materials recycling.

Photostabilization of Polymers

Photostabilization of Polymers
Author: J.F. Rabek
Publisher: Springer Science & Business Media
Total Pages: 607
Release: 2012-12-06
Genre: Science
ISBN: 9400907478

During the last two decades, the production of polymers and plastics has been increasing rapidly. In spite of developing new polymers and polymeric materials, only 40-60 are used commercially on a large scale. It has been estimated that half of the annual production of polymers is employed outdoors. Increasing the stability of polymers and plastics towards heat, light, atmospheric oxygen and other environmental agents and weathering conditions has always been a very important problem. The photochemical instability of most of polymers limits them to outdoor application, where they are photo degraded fast over periods ranging from months to a few years. To the despair of technologists and consumers alike, photodegrada tion and environmental ageing of polymers occur much faster than can be expected from knowledge collected in laboratories. In many cases, improved methods of preparation and purification of both monomers and polymers yield products of better quality and higher resistance to heat and light. However, without stabilization of polymers by applica tion of antioxidants (to decrease thermal oxidative degradation) and photostabilizers (to decrease photo-oxidative degradation) it would be impossible to employ polymers and plastics in everyday use.