Other radical reactions in irradiated polymers

The reactions of radicals formed in polymers by radiochemical, photochemical and mechanical methods have been reviewed and discussed recently by Butyagin et al. [214]. They identify the three main types of radical in solid polymers as 

Terminal radicals are usually the least stable and growing chain radicals the most stable. The temperature ranges of stability of polymer radicals are given in Table 11. 

Reactions other than recombination are possible for these radicals. Readicals of the type R—CH2, when formed, can be converted to central radicals by inter- or intramolecular hydrogen transfer this process is, however, limited at low temperatures. Growing chain radicals can depoly- 

Of course, all these radicals can also react by addition to unsaturated species, or by hydrogen abstraction from low molecular weight additives containing either unsaturation or labile hydrogen atoms. 

Macroradical reactivity has also been reviewed by Bresler and Kazbekov [225]. 

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