Polymer Analysis And Degradation

Polymer Analysis, Degradation & Stabilization

One of the most important features of the technical progress of this century has been deep and wide penetration of polymeric materials into all fields of human life. But, more than a half century of their use has revealed some shortcomings common to all of these materials. Probably the most important of these is the tendency of most synthetic polymers to degradation. Polymer degradation is, in fact, a series of chemical and physical transformations occurring in the polymer during service, processing or storage, which causes deterioration in valuable properties. Many factors are responsible for polymer degradation, including heat, UV radiation, biological agents and many others. These factors, either separately or together, cause complex processes including cracking, depolymerisation, cross-linking, oxidation, etc. They may cause considerable and often quite rapid deterioration of polymer properties leading to a sharp decrease in their useful life. This volume is organised to provide a wide coverage of new and traditional polymers and their behaviour during degradation, as well as the important chemical and engineering aspects of these materials relative to processing and performance in various applications.

New Developments in Polymer Analysis, Stabilisation & Degradation

This book introduces the techniques used for the analysis of polymers. It covers the main aspects of polymer science and technology; identification, polymerization, molecular weight, structure, surface properties, degradation and mechanical properties. * Clear explanations of each analytical technique * Describes the application of techniques to the study of polymers * Encourages learning through numerous self-assessment questions and answers * Structured for flexible learning

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 is a change in the properties -- tensile strength, colour, shape, etc -- of a polymer or polymer based product under the influence of one or more environmental factors such as heat, light or chemicals. These changes may be undesirable, such as changes during use, or desirable, as in biodegradation or deliberately lowering the molecular weight of a polymer. Such changes occur primarily because of the effect of these factors on the chemical composition of the polymer. In a finished product such a change is to be prevented or delayed. However, the degradation process can be useful from the view points of understanding the structure of a polymer or recycling/reusing the polymer waste to prevent or reduce environmental pollution. Polymers molecules are very large on the molecular scale which derive their unique and useful properties from their size.

Written by expert contributors from the academic and industrial sectors, this book presents traditional and modern approaches to polymer characterization and analysis. The emphasis is on pragmatics, problem solving and property determination; real-world applications provide a context for key concepts. The characterizations focus on organic polymer and polymer product microstructure and composition. Approaches molecular characterization and analysis of polymers from the viewpoint of problem-solving and polymer property characterization, rather than from a technique championing approach Focuses on providing a means to ascertaining the optimum approach or technique(s) to solve a problem/measure a property, and thereby develop an analytical competence in the molecular characterization and analysis of real-world polymer products Provides background on polymer chemistry and microstructure, discussions of polymer chain, morphology, degradation, and product failure and additive analysis, and considers the supporting roles of modeling and high-throughput analysis

The aim of this book is to familiarize the reader with the practical aspects of polymer analysis. A wealth of practical detail, including some detailed methods is included. The book covers not only the analysis of the main types of polymers and copolymers now in use commercially, but also the analysis of minor non-polymeric components of the polymer formulation, whether they be deliberately added, such as processing additives, or whether they occur adventitiously, such as moisture and residual monomers and solvent. A broad scheme for the examination of polymers is discussed in Chapter 2. Practically all of the major newer analytical techniques and many of the older classical techniques, have been used to examine polymers and their additive systems. As so many different polymers are now used commercially it is also advisable when attempting to identify a polymer to classify it by first separating it into pure polymeric and gross non polymeric fractions (Chapter Z) and then carrying out at least a qualitative elemental analysis and possible a quantitative analysis (Chapters 3 and 4) and then in some cases, depending on the elements found, to carry out functional group analysis (Chapters 6 and 9).