Synthesis and photochemical reaction of polyarylenesulfonium salts

A novel class of polyelectrolytes having triphenylsulfonio groups in its main chain was synthesized by the sulfoxide-acid system reaction from the corresponding aryl sulfoxide monomers. The photo-irradiation of ultraviolet light at the π-π* transition band resulted in the selective degradation of the polymer to the corresponding aryl or alkyl sulfide monomer. The photodegradation is accompanied by proton generation, which could be useful for the photoinitiated polymerization of epoxy compounds. The differences between the monomeric and the polymeric sulfonium salts in their photodegradation properties were examined on the basis of kinetics of photodegradation, quantum yields and the conversion in the photoinitiated polymerization of the epoxy monomer. The polymeric sulfonium salts are more effective than the monomeric ones due to larger ε (extinction coefficient) at the irradiation wavelength.