Processes in Highly Elastic Polymers

For a long time it was believed that the chemical bond can be broken only in some chemical reaction leading to a change in the structure of the molecule. Moreover, it was well known that the rate of chemical reactions can be substantially increased by means of physical influences (for example, heating). It was also known that chemical reactions themselves can be initiated by heating or irradiation by ultraviolet light. 

With the creation of modern sources of powerful radiations, active physical intervention into chemical processes acquired an especially great scope and led to the rapid development of a new branch of chemistry - radiation chemistry. Investigations of the free radicals formed during the irradiation of substances, known earlier from a number of chemical reactions, in particular, from polymerization reactions, also developed in close relationship with the successes of radiation chemistry. 

This young field of chemistry led to the creation of new concepts of the nature of the chemical bond and chemical reactivity, which permitted an understanding of the mechanism of many technically important, complex chemical and physicochemical processes (for example, the processes of synthesis and destruction of polymers) and made it possible to learn how to control them. 

The possibility of breaking or changing a chemical bond through physical influences has usually been related only to such influences as heating and irradiation. The breaking of chemical bonds by means of mechanical influences seemed impossible for a long time. 

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