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

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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 Stabilization

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

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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.

Thermal Degradation of Polymeric Materials

Thermal Degradation of Polymeric Materials PDF Author: Krzysztof Pielichowski
Publisher: iSmithers Rapra Publishing
ISBN: 9781859574980
Category : Science
Languages : en
Pages : 324

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Book Description
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.

Electrical Degradation and Breakdown in Polymers

Electrical Degradation and Breakdown in Polymers PDF Author: Len A. Dissado
Publisher: IET
ISBN: 9780863411960
Category : Science
Languages : en
Pages : 630

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Book Description
The book is in five parts: Part I introduces the physical and chemical structure of polymers and their breakdown; Part II reviews electrical degradation in polymers, and Part III reviews conduction and deterministic breakdown in solids. Part IV discusses the stochastic nature of break-down from empirical and modelling viewpoints, and Part V indicates practical implications and strategies for engineers. Much of the discussion applies to non-crystalline materials generally.

Polymer Photodegradation

Polymer Photodegradation PDF Author: J.F. Rabek
Publisher: Springer Science & Business Media
ISBN: 9401112746
Category : Technology & Engineering
Languages : en
Pages : 679

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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. The photochemical instability of most polymers limits their outdoor application as they are photodegraded quickly over periods from months to a few years. To the despair of technologists and consumers alike, photodegradation and environmental ageing of polymers occur much faster than can be expected from knowledge collected in laboratories. In order to improve polymer photostability there has been a very big effort during the last 30 years to understand the mechanisms involved in photodegradation and environmental ageing. This book represents the author's attempt, based on his 25 years' experience in research on photodegradation and photo stabilization, to collect and generalize a number of available data on the photodegradation of polymers. The space limitation and the tremendous number of publications in the past two decades have made a detailed presentation of all important results and data difficult. The author apologizes to those whose work has not been quoted or widely presented in this book. Because many published results are very often contradictory, it has been difficult to present a fully critical review of collected knowledge, without antagonizing authors. For that reason, all available theories, mechanisms and different suggestions have been presented together, and only practice can evaluate which of them are valid.

Photodegradation of Polymers

Photodegradation of Polymers PDF Author: Jan F. Rabek
Publisher: Springer Science & Business Media
ISBN: 3642800904
Category : Science
Languages : en
Pages : 222

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Book Description
In this book on physical characteristics and practical aspects of polymer photodegradation Rabek emphasizes the experimental work on the subject. The most important feature of the book is the physical interpretation of polymer degradation, e.g. mechanism of UV/light absorption, formation of excited states, energy transfer mechanism, kinetics, dependence on physical properties of macromolecules and polymer matrices, formation of mechanical defects, practics during environmental ageing. He includes also some aspects of polymer photodegradation in environmental and space condition.

Polymer Degradation and Stabilisation

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

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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.

Degradable Polymers

Degradable Polymers PDF Author: G. Scott
Publisher: Springer Science & Business Media
ISBN: 9401105715
Category : Technology & Engineering
Languages : en
Pages : 284

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Book Description
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.

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

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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.

Thermal Degradation of Polymeric Materials

Thermal Degradation of Polymeric Materials PDF Author: Krzysztof Pielichowski
Publisher: Elsevier
ISBN: 0128231424
Category : Technology & Engineering
Languages : en
Pages : 379

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Book Description
Thermal Degradation of Polymeric Materials, Second Edition offers a wealth of information for polymer researchers and processors who require a thorough understanding of the implications of thermal degradation on materials and product performance. Sections cover thermal degradation mechanisms and kinetics, as well as various techniques, such as thermogravimetry in combination with mass spectroscopy and infrared spectrometry to investigate thermal decomposition routes. Other chapters focus on polymers and copolymers, including polyolefins, styrene polymers, polyvinyl chloride, polyamides, polyurethanes, polyesters, polyacrylates, natural polymers, inorganic polymers, high temperature-resistant and conducting polymers, blends, organic-inorganic hybrid materials, nanocomposites, and biocomposites. Finally, other key considerations such as recycling of polymers by thermal degradation, thermal degradation during processing, and modelling, are discussed in detail. Explains mechanisms of polymer degradation, making it possible to understand and predict material behavior at elevated temperatures Offers systematic coverage of each polymer group that is supported by data detailed explanations and critical analysis Investigates thermal decomposition routes in new materials, such as organic-inorganic hybrid materials and polymer nanocomposites

Physical Properties of Polymers

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

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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.