CATIONIC PHOTOPOLYMERIZATION OF P-METHYLSTYRENE INITIATED BY PHOSPHONIUM AND ARSONIUM SALTS

Phenacyl benzyl phosphonium, and arsonium salts are useful photoinitiators for cationic polymerization of p-methylstryene (PMS); photosensitization of phenacyl triphenyl phosphonium salt by pyrene or N-methylphenothiazine enhances the rate of polymerization. Triphenylphosphine and triphenylarsine inhibits the polymerization of PMS. The effects of photolysis time, light intensity, initiator and sensitizer chemical structure on the rate of polymerization by salts of the above cations with hexafluoroantimonate (SbF6-) or hexafluorophosphate (PF6-) is presented.