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One Electron Transposition Initiation Reactions

المؤلف:  A. Ravve

المصدر:  Principles of Polymer Chemistry

الجزء والصفحة:  ص163-164

2026-01-15

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One Electron Transposition Initiation Reactions

Some radical sources, will, in the presence of oxidizing agents, or light, or heat energy, initiate cationic polymerizations of monomers, like n-butyl vinyl ether. Those that are most readily oxidized are carbon atom centered radicals that have substituents like benzyl, allyl, alkoxy, or structures with nitrogen or sulfur. Also, radicals that are formed by addition of other radicals to alkyl vinyl ethers are particularly reactive. Oxidants that can be used in these reactions are salts, like (C₆H₅)₂I+PF₆  . Such salts oxidize the radical and also supply the counter-ions, as shown below [54]:

What happens to the final radical is uncertain. High conversions were reported in polymerizations of n-butyl vinyl ether in the presence of azobisisobutyr onitrile (as a source of radicals) with (p- tolyl)₂ I PF₆ at 50C [55]. The aboveisanillustration of a thermal process [12]. Free radicals can also be generated with the aid of UV light. This, for instance, was done with a UV light decomposition of benzoin methyl ether in the presence of an oxidizing salt [56]: