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.

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.

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.

Accelerated Aging: Photochemical and Thermal Aspects represents the culmination of more than 40 years of research by noted scientist Robert L. Feller. The book focuses on the long-term performance of materials such as wool, dyes, and organic compounds; their resistance to change when exposed to environmental factors such as oxygen, ozone, moisture, heat, and light; and their physical durability with handling and use over time. Processes of deterioration are discussed based on speeded-up laboratory studies designed to clarify the chemical reactions involved and their physical consequences.

My heart sank when I was approached by Dr Hastings and by Professor Briggs (Senior Editor of Materials Science and Technology and Series Editor of Polymer Science and Technology Series at Chapman & Hall, respectively) to edit a book with the provisional title Handbook of Poly propylene. My reluctance was due to the fact that my former book [1] along with that of Moore [2], issued in the meantime, seemed to cover the information demand on polypropylene and related systems. Encour aged, however, by some colleagues (the new generation of scientists and engineers needs a good reference book with easy information retrieval, and the development with metallocene catalysts deserves a new update!), I started on this venture. Having some experience with polypropylene systems and being aware of the current literature, it was easy to settle the titles for the book chapters and also to select and approach the most suitable potential contributors. Fortunately, many of my first-choice authors accepted the invitation to contribute. Like all editors of multi-author volumes, I recognize that obtaining contributors follows an S-type curve of asymptotic saturation when the number of willing contributors is plotted as a function of time. The saturation point is, however, never reached and as a consequence, Dear Reader, you will also find some topics of some relevance which are not explicitly treated in this book (but, believe me, I have considered them).

The increasing environmental and health concerns owing to the use of large quantities of water and hazardous chemicals in conventional textile finishing processes has lead to the design and development of new dyeing strategies and technologies. Sustainable Practices in the Textile Industry comprises 13 chapters from various research areas dealing with the application of different sustainable technologies for enhancing the dyeing and comfort properties of textile materials with substantial reduction in wastewater problems. Chapters focus on the sophisticated methods for improving dye extraction and dyeing properties which will minimize the use of bioresource products. This book also brings out the innovative ways of wet chemical processing to alleviate the environmental impacts arising from this sector. This book also discusses innovations in eco-friendly methods for textile wet processes and applications of enzymes in textiles in addition to the advancements in the use of nanotechnology for wastewater remediation.