Anthracene electron-transfer photosensitizers for onium salt induced cationic photopolymerizations

This article describes the synthesis of several derivatives of anthracene (AN) and their evaluation as electron-transfer photosensitizers for onium salt induced cationic photopolymerizations. The synthetic methods that were employed involved straightforward and high yield routes to these derivatives. Using Fourier transform real-time infrared spectroscopy (FT-RTIR), the photoinduced polymerizations of several model epoxide and vinyl ether monomers were examined in the presence and absence of the anthracene photosensitizers. It was observed that anthracene derivatives bearing electron-donating substituents markedly accelerated the rates of all the UV irradiation induced photopolymerizations in which diaryliodonium, triarylsulfonium and dialkylphenacylsulfonium salt photoinitiators were used. In each case, the greatest acceleration of the rate of the polymerizations occurred when 9,10-dialkoxyanthracenes were employed as photosensitizers.