An Exploration of General Trends in Molecular Weight Distribution in Coordinative Chain Transfer Polymerization

Herein a kinetic model is derived for coordinative chain transfer polymerization (CCTP) which includes transfer of polymer chains to a metal based chain transfer agent (CTA) in order to produce olefin block copolymers (OBC). The model was based on the presence of 2 different monomers and the characteristics of the PDI curve were studied and interesting results are gained. 3 important characteristics of PDI are the maximum, minimum and rate of marching toward 2. The influence of the rate constants on each one was studied and general trends were obtained expressing the role of chain transfer constants on each characteristic of the PDI curve, in the form of equations mentioned in the article. At the end, polymerization data from bis(phenoxyimine)zirconium catalyst system is presented from the literature to demonstrate these effects.