KINETICS OF ZIEGLER PROPYLENE POLYMERIZATION

Rate studies were done on the polymerization of propylene with the TiCl//3-diethyl-aluminum chloride catalyst system. A yield equation was developed which fits experimental data closely. Rate correlations show that the initial rate is exponentially related to the TiCl//3/alkyl ratio. Water and other active hydrogen compounds reduce rate; hydrogen increases rate. A ″bimetallic″ mechanism is proposed which views catalyst activation as consisting of three equilibria, followed by a propagation step where an alkyl group is transferred to the growing chain, and a realkylation of the hydride that remains after the propagation step.