Mechanisms of Polymer Degradation and Stabilisation

Mechanisms of Polymer Degradation and Stabilisation PDF Author: G. Scott
Publisher: Springer Science & Business Media
ISBN: 9401138389
Category : Technology & Engineering
Languages : en
Pages : 336

Get Book Here

Book Description
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.

Mechanisms of Polymer Degradation and Stabilisation

Mechanisms of Polymer Degradation and Stabilisation PDF Author: G. Scott
Publisher: Springer Science & Business Media
ISBN: 9401138389
Category : Technology & Engineering
Languages : en
Pages : 336

Get Book Here

Book Description
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.

Polymer Degradation and Stabilization

Polymer Degradation and Stabilization PDF Author: W. L. Hawkins
Publisher: Springer Science & Business Media
ISBN: 3642693768
Category : Technology & Engineering
Languages : en
Pages : 129

Get Book Here

Book Description
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.

Polymer Degradation and Stabilisation

Polymer Degradation and Stabilisation PDF Author: Norman Grassie
Publisher: CUP Archive
ISBN: 9780521357975
Category : Science
Languages : en
Pages : 236

Get Book Here

Book Description
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.

Fundamentals of Polymer Degradation and Stabilization

Fundamentals of Polymer Degradation and Stabilization PDF Author: N.S. Allen
Publisher: Springer Science & Business Media
ISBN: 9781851667734
Category : Technology & Engineering
Languages : en
Pages : 218

Get Book Here

Book Description
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.

Degradation and Stabilisation of PVC

Degradation and Stabilisation of PVC PDF Author: J. Owen
Publisher: Springer Science & Business Media
ISBN: 9400956185
Category : Technology & Engineering
Languages : en
Pages : 325

Get Book Here

Book Description
Polyvinyl chloride has played a key role in the development of the plastics industry over the past 40 years and continues to be a polymer of major importance. The reasons for its enormous versatility and range of application derive from a combination of the basic structure which gives rise to a relatively tough and rigid material and its ability to accept a range of plasticisers and other additives which can modify its physical characteristics to produce a range of flexible products. Two major problems, however, have tested the skill and ingenuity of PVC technologists since earliest times. One is the thermal instability of the material at the temperatures required for melt processing and fabrication, and the second is the photochemical instability which until recently has limited the potentially large range of outdoor applications. Both problems have been handled in a commercially satisfactory way by the gradual development of a range of stabilisers, lubricants and other processing aids and the high quality material which has resulted has led to massive utilisation of PVC by industry. Totally adequate stabilisation requires a detailed understanding of the mechanisms by which degradation processes are initiated and propagated. Although great advances have been made in this respect in recent years the problem remains incompletely understood. This book presents an account of the present position and the problems which remain to be solved.

Stabilization of Polymeric Materials

Stabilization of Polymeric Materials PDF Author: Hans Zweifel
Publisher: Springer Science & Business Media
ISBN: 3642803059
Category : Science
Languages : en
Pages : 225

Get Book Here

Book Description
Plastics are used worldwide in everyday life, e.g. as food packaging, electronics, construction, automotive parts, and household appliances. To produce these products with the desired service lifetimes the use of suitable stabilizers is necessary. This book provides a concise and comprehensive overview of the basic mechanisms of plastic degradation processes caused by heat and light. At its core is a detailed description of the stabilization of different polymers, including an explanation of stabilization mechanisms and the influence of commonly used additives such as fillers, flame retardents and pigments on the stability of plastic. Every polymer scientist, material technologist, or application engineer dealing with the design of the properties of plastics will benefit from this new overview.

Photostabilization of Polymers

Photostabilization of Polymers PDF Author: J.F. Rabek
Publisher: Springer Science & Business Media
ISBN: 9400907478
Category : Science
Languages : en
Pages : 607

Get Book Here

Book Description
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.

Physical Properties of Polymers

Physical Properties of Polymers PDF Author: James E. Mark
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 430

Get Book Here

Book Description
The contents have been divided into sections on physical states of polymers and characterization techniques. Chapters on physical states include discussions of the rubber elastic state, the glassy state, melts and concentrated solutions, the crystalline state, and the mesomorphic state. Characterization techniques described are molecular spectroscopy and scattering techniques.

Oxidation Inhibition in Organic Materials

Oxidation Inhibition in Organic Materials PDF Author: Jan Pospisil
Publisher: CRC Press
ISBN: 9780849347689
Category : Science
Languages : en
Pages : 398

Get Book Here

Book Description
This two volume publication provides an overview of processes developed to inhibit oxidative deterioration of organic materials. It discusses aspects of auto-oxidation, photo-oxidation and combustion, the major mechanisms involved, oxidation inhibitors classes, and practices in oxidation inhibition. The books include physical phenomena in polymer oxidation, and thermoanalytical methods for studying oxidation inhibition. Covered are analytical methods for inhibitors in organic materials, and scientific and technical prospects in the stabilization of organic materials. This comprehensive title is useful for investigators and students at all levels who have interest in polymer sciences.

Degradation and Stabilisation of Polyolefins

Degradation and Stabilisation of Polyolefins PDF Author: Norman S. Allen
Publisher:
ISBN:
Category : Alkenes
Languages : en
Pages : 430

Get Book Here

Book Description