Bivalent monomer bearing styryl and five-membered cyclic dithiocarbonate moieties for orthogonal radical and cationic ring-opening polymerizations

We synthesized a novel bivalent monomer 1 bearing 4-vinylbenzyl group and five-membered cyclic dithiocarbonate. This monomer 1 was polymerized orthogonally by free radical polymerization to afford polystyrene 1a bearing a five-membered cyclic dithiocarbonate moiety in the side chain. On the other hand, cationic ring-opening polymerization of five-membered cyclic dithiocarbonate in the monomer 1 successfully proceeded, resulting in a narrow molecular weight distribution of polydithiocarbonate 1b bearing a 4-vinylbenzyl group in the side chain. Furthermore, post-polymerizations of 1a and 1b maintaining the polymerizable functionality were carried out respectively by suitable polymerization methods. The five-membered cyclic dithiocarbonate of 1a underwent cationic ring-opening polymerization with a high molar ratio of methyl trifluoromethanesulfonate at a high temperature compared to the case of monomer 1, whereas radical polymerization of the 4-vinylbenzyl group of 1b successfully proceeded under the almost same conditions as the case of monomer 1. These post-polymerizations achieved the synthesis of corresponding networked polymers 2a and 2b.