Monomeric and polymeric carbazole photosensitizers for photoinitiated cationic polymerization

Carbazole monomers bearing cationically polymerizable vinyl, vinyl ether an d epoxide groups are rapidly and efficiently polymerized by UV irradiation in the presence of onium salt photoinitiators. Moreover these monomers were observed to function as efficient photosensitizers for the photolysis of t he onium salts. In this article, the use of these polymerizable photosensit izers for the photopolymerizations of epoxide and vinyl ether monomers is r eported. The inclusion of only a small amount of the monomeric carbazole ph otosensitizer is effective in markedly accelerating the photopolymerization of the bulk monomer. The broadening of the spectral response through the u se of these photosensitizers accounts for the observed rate enhancement of these polymerization reactions. Polymers prepared by the polymerization of the monomeric photosensitizers also exhibit excellent photosensitization ac tivity.