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.

Recent development of plasmonic photocatalysts for photodegradation of organic pollutants / Tao Li, Huijuan Jing and Deliang Chen -- Photodegradation of profoxydim herbicide; kinetics, phytotoxicity bioassay and determination of relevant parameters by QSAR models / P. Sandín-España, J. J. Villaverde, B. Sevilla-Morán, M. J. Patiño-Ropero, J. L. Alonso-Prados and I. Santín-Montanyá -- Photodegradation mechanism of cyanine dyes / Masanori Fuyuki -- Photochemistry of cobalamins / Kiran Qadeer, Adeel Arsalan, Zubair Anwar and Iqbal Ahmad -- Two dimensional (2D) tungsten disulfide (WS2) as a cocatalyst for degradation of organic pollutants / S. V. Prabhakar Vattikuti -- Photodegradation of water contaminants and humic acids of different nature and genesis using various light sources / Irina V. Sokolova and Olga N. Tchaikovskaya.

Photodegradation of Water Pollutants, the only complete survey available of current photocatalytic methods for treating water pollutants, covers all aspects of light-stimulated detoxification. Ideal for researchers and students, this new book explains methods for pollution treatment that have proven more effective than conventional biodegradation. Photodegradation of Water Pollutants examines advanced oxidation processes that have been successful in treating the chemical substances produced by industrial effluents and intensive agriculture. These oxidation processes include irradiation with ultraviolet or visible light, the use of homogenous sensitizers, such as dyes, and the use of heterogeneous photocatalysts, such as dispersed semiconductors. In addition, Photodegradation of Water Pollutants addresses the naturally occurring self-cleaning of some pollutants in sunlit surface waters, as well as several alternative non-photochemical approaches to water treatment. Available treatment options are discussed for the main groups of water pollutants, including toxic inorganic ions (cyanides, heavy metals), hydrocarbon derivatives (oil spills, surfactants, pulp and paper wastes), halocarbons, organo-N, organo-P, and organo-S compounds. The text also contains a unique section on the economics of advanced oxidation pollution treatments.

Degradation of Polymers

There are five main subject areas in this volume in the series on medicinal chemistry. The first is a review of the understanding of Alzheimer's disease and the development of drugs for its treatment; the second, looking at recent efforts in modifying a naturally occuring anticancer (campothecin) for chemotherapy; the third covers the problem of getting a drug to a specific site within the context of phosphates and phosphonates; a survey of sterilization using aldehydes for the destruction of microbes both inside and outside the human body is reviewed in the fourth; and the last chapter is an account of the progress made in the biologically active enantiomer for complex synthetic asymmetric drug molecules.

Based on a training course developed by Dr. Joseph T. Piechocki and other experts in this field whose contributions appear in this book for two International Meetings on the Photostability of Drugs and Drug Products, this text clarifies the guidelines set by the International Conference on Harmonization (ICH) and provides a comprehensive background

Since Pasteur in 1846, scientists have been aware that many drugs are photoreactive, but until recently research in this area had been somewhat limited. However, since the introduction of acutely sensitive analytical methods, the realisation of the need to identify the photochemical properties of a potential drug as early in its development as possible and the increased attention to the phototoxic effect of drugs, more details are becoming available. Drugs: Photochemistry and Photostability presents the basic elements of the science, and serves as an excellent introduction to this emerging field of photochemistry. Detailed experimental conditions for photostability studies are given, along with a discussion of the recently implemented ICH Guidelines for drug photostability. With contributions from international experts in the field and including a comprehensive literature review, this book provides all the up-to-date information needed by researchers in many fields, especially medicinal and pharmaceutical chemistry.