Polymer Products

Degradation reactions grouped under the heading chemical attack include oxidation hydrolysis, halogenation and other reactions. They also include some purely physical interactions between materials and fluids, dominated by the absorption of fluid into the material or vice versa. One particular mechanism described in some detail is acid induced stress corrosion cracking, which is the most frequent cause of premature failure of GRP products, and where the principle degradation reaction is between the fluid and the glass fibres. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.

This book is derived from a recent project sponsored by the Polymer Engineering Directorate of the SERC and carried out at the University of Lancaster under the joint auspices of the Departments of Chemistry and Engineering. The project set out to provide a novel type of teaching material for introducing polymers and their uses to students, especially of engineering. Case studies of real examples of polymers at work are used, so the student or teacher can start with a successful and well-designed product and work backwards to its origins in the market, in design and material selection and in the manufacturing process. The philosophy is that such an approach captures interest right at the start by means of a real example and then retains it because of the relevance of the technical explanation. This after all is what most of us do habitually; we turn to examples to make our point. The hope is that subject matter with a somewhat notorious reputation among engineers, such as aspects of polymer chemistry and the non-linear behaviour of polymers under mechanical loading will be fairly painlessly absorbed through the context of the examples. Each study becomes a separate chapter in the book. The original studies, and hence the present chapters, vary in length because different topics demanded different approaches. No attempt has been made to alter this, or to adopt a standardized format because to have done so would have interfered with the vitality of the original work.

This new volume presents leading-edge research in the rapidly changing and evolving field of polymer science as well as on chemical processing. The topics in the book reflect the diversity of research advances in the production and application of modern polymeric materials and related areas, focusing on the preparation, characterization, and applications of polymers. Also covered are various manufacturing techniques. The book will help to fill the gap between theory and practice in industry.

The combined effects of oxidising media and heat result in degradation by thermo-oxidation. The principles and cases described in this review emphasise long term degradation in service. Two additional phenomena that influence thermo-oxidation are also described: catalysis by certain metal ions, and the influence of stress. An additional indexed section containing several hundred abstracts from the Polymer Library gives useful references for further reading.

Use of polymers in product design has continued to grow at a rate unrivalled by conventional materials such as metal, ceramics or glass. More polymeric materials are becoming available to the designer, and this report highlights the need for caution in new design work, for careful use of new materials, and for awareness of the product environment. An additional indexed section containing several hundred abstracts from the Rapra Polymer Library database gives useful references for further reading.

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.

Plastics and rubber materials, or polymers, are increasingly the first choice of engineers when reliable, cost-effective performance and safety are essential. The volume of polymers used in the Western economy now exceeds that of metals, which requires today's engineering students to have a thorough grounding in the properties and applications of polymeric materials. The first chapters of Engineering with Polymers explain what polymers are, how they behave, and how articles are made from them. The authors then show how the standard engineering techniques of stress analysis, structures, fluid mechanics, heat transfer and design can be adopted or adapted to cover plastics and rubber materials. The book ends with chapters detailing interactions between processing and properties, and a description of a variety of approaches to designing plastics products, from practical advice to the use or further development of theoretical principles, backed up by examples and case studies. The book is aimed at mechanical engineering students and design engineers in industry and also at materials' and chemical engineers.