Copolymerization of Methyl Methacrylate with Styrene Initiated by Thiol

Tert.– dodencanethiol can initiate the copolymerization of methyl methacrylate (MMA) and styrene (St) near room temperature. Experimental results indicate that tert.– dodencanethiol (RSH) influences the initial rate of copolymerization (Rp) only insignificantly, when its concentration ranges from 4.3 × 10−4 to 2.7 × 10−2 mol/1; Rp increases as [MMA] in monomer composition is increased; the activation energy of the copolymerization at 30°C ∼ 45°C is determined to be 56.4kJ / mol; the fact that the molecular weight of the copolymer decreases as [RSH] is increased indicated that thiol acts in the reaction not only as an initiator but also as a chaintransfer agent.