Estimation of Apparent Kinetic Constants of Individual Site Types for the Polymerization of Ethylene and α-olefins with Ziegler-Natta Catalysts

This article proposes a method to quantify the polymerization kinetics of ethylene and alpha-olefins with commercial TiCl4/MgCl2 Ziegler-Natta catalysts. The method determines the leading apparent polymerization kinetic constants for each active site in a Ziegler-Natta catalyst by simultaneously fitting the instantaneous polymerization rate, cumulative polymer yield, and polymer molecular weight distribution measured at different times during a series of semi-batch polymerization experiments. This approach quantifies the behavior of olefin polymerization with multisite catalysts using the least number of adjustable parameters needed to consistently model polymerization kinetics and polymer microstructural data.