Aging And Stabilization Of Polymers

The need for a broad development of the production of polymer ma terials has become evident. All these materials are subject to various types of aging (destruction); hence, stabilizers which permit the stor age, reprocessing, and use of polymer materials without any appreci able change in their properties must be introduced into them. In recent years, this problem of stabilizing polymers has attracted the attention of many scientists and technologists, both in the USSR and abroad. The scientific basis of the foreign studies will be found in a number of theo retical premises, but chiefly the theory of chain reactions with un branched chains. In the Soviet Union, the concepts of Academician N. N. Semenov on chain reactions with degenerate branches have become the starting point of theoretical studies of the stabilization and destruction of polymers. Soviet scientists have developed a theory of critical concentrations of antioxidants and have shown that the processes of stabilization have a very complex chemical character. The nature of the polymers them selves greatly affects these processes and consequently, different stabil izers are required for polymers of different structures. In addition, it has been shown that the antioxidants used thus far can not only cause chain termination, but can also initiate oxidation and give rise to de generate branches.

Aging of Polymers, Polymer Blends & Polymer Composites

Plastics are used worldwide in everyday life, e.g. as food packaging, electronics, construction, automotive parts, and household appliances. To produce these products with the desired service lifetimes the use of suitable stabilizers is necessary. This book provides a concise and comprehensive overview of the basic mechanisms of plastic degradation processes caused by heat and light. At its core is a detailed description of the stabilization of different polymers, including an explanation of stabilization mechanisms and the influence of commonly used additives such as fillers, flame retardents and pigments on the stability of plastic. Every polymer scientist, material technologist, or application engineer dealing with the design of the properties of plastics will benefit from this new overview.

Photodegradation and light stabilization are very important aspects of polymer aging. Polymer degradation includes different types of processes: thermodegradation, oxidation, acting of ozone, photodegradation, radiation, hydrolysis, mechanical degradation, and biodegradation. It is very important to know the mechanism of polymer degradation in order to select stabilizers against the degradation. This volume presents the analysis of achievements in the field of photodegradation of polymers. It includes, first of all, data of Russian investigators who have decisively contributed in the development of this field of knowledge (the schools headed by academicians V.V. Korshak, N.M. Emanuel, N.S. Enikolopov, A.A. Berlin, and many others).

Twenty-one papers collected here report on the latest work in polymer ageing, looking at aspects including the ageing of polyester resin under moisture action, kinetic peculiarities of synthesis of Adamantan- containing polyamidoacids and polyimides, the influence of intensive mechanical treatment on decomposition of barium peroxide, and ecological aspects of manufacture and application of highly pure liquid substances. Biodegradable blends of starch and cellulose derivatives, the quantum chemical calculation of components of biosynthesis of adrenaline, low combustible poly(vinyl chloride) compositions with mixtures of plasticiSers, and inhibited oxidation of polypropylene melt are some other topics discussed.