Direct Radical Copolymerizations of Thioamides To Generate Vinyl Polymers with Degradable Thioether Bonds in the Backbones.

Direct radical addition reactions of thiocarbonyl (C═S) groups unaccompanied by β-scission have rarely been reported despite their potential for constructing various sulfur-containing compounds. Herein, we report direct radical copolymerizations of the C═S double bonds of simple thioamide derivatives and the C═C double bonds of common vinyl monomers to produce novel degradable vinyl polymers that contain thioether units in the backbones. In particular, N-acylated thioformamides copolymerized smoothly with various vinyl monomers, such as methyl acrylate, vinyl acetate, ,-dimethylacrylamide, and styrene. RAFT copolymerization was also successfully mediated. The resultant copolymers had high glass transition temperatures and were readily degradable under ambient conditions. This work will expand the potential for use of thiocarbonyl compounds in radical reactions and develop novel poly(thioether)-vinyl polymer hybrid materials with unusual properties.