S-BENZOYL O-ETHYL XANTHATE AS A NEW PHOTOINITIATOR - PHOTOPOLYMERIZATION AND LASER FLASH-PHOTOLYSIS STUDIES

A new sulfur-containing photoinitiator, S-benzoyl O-ethyl xanthate (2) has been prepared and used for the photopolymerization of methyl methacrylate (MMA). The photoinitiation property of 2 has been examined by conventional polymerization methods and nanosecond laser flash photolysis studies. Upon 308 nm laser pulse excitation, 2 gave rise to transients with absorption maxima at 350 and 650 nm, assigned to the benzoyl radical (3) and (ethoxythiocarbonyl)thiyl radical (4), respectively, on the basis of their quenching by nitroxy radicals and spectral similarity to analogous species, reported in the literature.