Thienothiophene and biphenyl based conjugated porous polymer as a photocatalyst for visible light induced free radical and cationic polymerization

Abstract

Over the last few decades, photopolymerization has been the center of great attention owing to a variety of desirable features such as mild reaction conditions, cost efficiency and especially, spatiotemporal controllability. In particular, visible light induced polymerizations have been attracting considerable attention due to the concerns on cost efficiency, light penetration and environment safety. In this work, a crosslinked conjugated polymer, TT-BP, was designed and synthesized by Pd (0) catalyzed Suzuki coupling reaction. It was used as a photocatalyst for visible light induced free radical and cationic polymerizations in the presence of diphenyliodonium salt. The reactions were performed for 8 and 24 h in high yields, for which the photocatalyst TT-PB was used repeatedly for each reaction. The maximum conversion reached to 76 % in free radical polymerization of MMA, while the maximum conversion was obtained in cationic polymerization of IBVE with 82 %. This report on reusable conjugated polymer that have been used as a photocatalyst during free-radical and cationic photopolymerizations may lead to the emergence of a new perspective for photocatalyst and photopolymerization processes.