Statistically Syndioselective Coordination (Co)polymerization of 4-Methylthiostyrene

Abstract

The homopolymerization of a polar monomer, 4-methylthiostyrene (MTS), was successfully achieved by a rare-earth metal based catalyst in the highest activity of 45.1 × 104 g molY–1 h–1 and the excellent syndioselectivity (rrrr > 99%). The polymerization was rather controllable that the resultant poly(methylthiostyrene)s (PMTS) had molecular weights comparable to the theoretic ones reaching up to 1.7 × 105 while the molecular weight distributions were narrow (PDI = 1.3–1.9). Moreover, the copolymerization of this polar MTS with the nonpolar styrene (St) performed fluently under various MTS-to-St ratios in a quasi-living mode. The monomer reactivity ratios were rMTS = 1.08 and rSt = 0.77, following the first Markov statistics, and was close to the ideal random copolymerization. Therefore, a series of unprecedented statistical random copolymers, P(St-r-MTS)s, where the compositions were strictly closed to the monomer fed ratios, had been accessed. Strikingly, both monomer sequences remained highly syndiotacti...