Polymerization studies using modified Ziegler-Natta catalysts: 1. Polymerization of vinyl chloride

The polymerization of vinyl chloride by a number of modified Ziegler-Natta catalysts has been investigated. The most effective catalyst system is the soluble system prepared from vanadium oxytrichloride, tri-isobutylaluminium, and tetrahydrofuran. All three components are necessary for the formation of an active catalyst. The kinetics of the polymerization of vinyl chloride by this catalyst system has been examined at 30°C, and the dependence of the overall rate of polymerization on the transition halide concentration, aluminium alkyl concentration, monomer concentration and temperature established. Kinetic and copolymerization studies indicate that the polymerization process is not free radical in nature but is similar to that encountered in more conventional Ziegler-Natta systems.