Ethylene Polymerizations Using Parallel Pressure Reactors and a Kinetic Analysis of Chain Transfer Polymerization

Abstract

We demonstrate a method for high-throughput catalyst screening using a parallel pressure reactor starting from the initial synthesis of a nickel α-diimine ethylene polymerization catalyst. Initial polymerizations with the catalyst lead to optimized reaction conditions, including catalyst concentration, ethylene pressure and reaction time. Using gas-uptake data for these reactions, a procedure to calculate the initial rate of propagation (k p ) is presented. Using the optimized conditions, the ability of the nickel α-diimine polymerization catalyst to undergo chain transfer with diethylzinc (ZnEt 2 ) during ethylene polymerization was investigated. A procedure to assess the ability of the catalyst to undergo chain transfer (from molecular weight and 13 C NMR data), calculate the degree of chain transfer, and calculate chain transfer rates (k e ) is presented. Video LinkThe video component of this article can be found at