Determination of the transfer constant of α-thioglycerol in methyl methacrylate free-radical polymerization

Using the Mayo and the Clay-Gilbert method, the transfer rate coefficient of α-thioglycerol (TG) was determined at 50°C for the polymerization of methyl methacrylate (MMA) in a 3 mol · L^?1 tetrahydrofuran solution using different amounts of 2,2′-azoisobutyronitrile (AIBN) as initiator. The transfer rate coefficient was found to be independent of the initiator concentration and higher by a factor of 1.6 when obtained according to the Clay-Gilbert method compared to the Mayo method.