Die thermische polymerisation von methylmethacrylat, 3. Verhalten des ungesättigten dimeren bei der polymerisation

The thermal polymerization of methyl methacrylate is accompanied by the formation of appreciable amounts of an unsaturated dimer (H-1). The behaviour of H-1 during homopolymerization in presence of an initiator at 60, 80 and 100°C and during copolymerization with MMA in presence of an initiator at 60°C are investigated. The rate of (H-1)-homopolymerization is very low. The transfer constant to monomer H-1 is about CH-1 = 3·10−3 at 80°C as received from Pn-determinations. The termination is essentially by disproportionation. The copolymerization parameters as resulting from polymerizations with labeled MMA at 60°C are rMMA = 1,8 and rH-1 = 0,33, respectively.