Light‐induced cationic polymerization

Abstract

AbstractMechanistic studies concerning the initiation of cationic chain reactions with the aid of diaryliodonium and triarylsulphonium salts are reviewed and recent results are presented. Laser flash photolysis in combination with pulse radiolysis experiments revealed evidence for a triplet path occurring parallel to the singlet deactivation route of electronically excited diphenyliodonium ions. The radical cations PhI+− and Ph2S+− were found to react selectively with nucleophiles, the former being more reactive than the latter. Moreover, various aspects of the photo‐initiated free radical‐promoted cationic polymerization of typical monomers such as tetrahydrofuran and butyl vinyl ether with the aid of acylphosphine oxides and other free radical initiators are discussed.