SYNTHESIS OF CONTROLLED BLOCK AND GRAFT COPOPOLYMERS .2. BLOCK AND GRAFT-POLYMERIZATION INITIATED BY MONOHALO CONTAINING POLYMER MANGANESE CARBONYL SYSTEMS

Block polymerization of methyl methacrylate initiated with monohalo-terminated polystyrene/manganese carbonyl systems was investigated. The rate of polymerization was lower than that of the trihalo-terminated polystyrene/manganese carbonyl system. The molecular weight of the block copolymers obtained was independent of the conversion. To define the polymerization mechanism, 1-bromobutane was employed as a model compound for monohalo-terminated polystyrene. Polymerization kinetics followed a modified rate equation based on the Michaelis-Menten mechanism. Graft polymerization of methyl methacrylate initiated with chloromethylstyrene-styrene copolymer/manganese carbonyl was also carried out. The polymerization behavior was strongly affected by the concentration of manganese carbonyl.