Photoinitiated and aprotonically initiated polymerization of olefins by Lewis acids

A survey and discussion of recent problems in interpretation of the mechanism of olefin polymerization by Lewis acids is presented from the point of view of new results obtained by study of physicochemical transformations which proceed in interaction of catalysts with olefins. Opinions related to the photo‐chemically initiated cationic polymerization have been further defined by the study of formation and composition of complexes as well as by analysis of oxidation‐reduction processes proceeding under the effect of light on the reaction mixture. The formation of radicals under the effect of visible light in the presence of Lewis acids was proved with several monomers other than isobutylene. During investigation of the role of products from the photooxidation‐reduction processes in the polymerization of isobutylene, it has been found that strongly basic reducing agents, such as butyllithium, cause the polymerization of isobutylene in the presence of halides of tetravalent transition metals. Also analyzed are the aspects of utilization of the photochemically induced polymerization in development of new technological procedures for manufacturing of high molecular weight polyisobutylene and butyl rubber under economically advantageous conditions.