Molecular Kinetic Study of “Chain Shuttling” Olefin Copolymerization

Abstract

Statistical olefin block copolymers (OBCs) with “hard” and “soft” linear low-density polyethylene (LLDPE) blocks can be synthesized by tandem catalysis under “coordinative chain transfer polymerization” (CCTP) conditions. This process, disclosed in 2006 and commonly referred to as “chain shuttling copolymerization” (CSCP), is now exploited commercially by Dow Chemical, to produce thermoplastic elastomers with the Infuse trade name. Whereas the general kinetic principles of CSCP as well as the fundamental physical properties of the products are rather well-understood, the details are still poorly defined, to the point that even average block numbers and lengths of commercial Infuse grades are not available in the public domain. In this paper, we report the results of a molecular kinetic investigation in which high throughput experimentation tools and methods were employed to unravel the microstructure and architecture of these materials. The problem was factored in two parts. First, each of the two catalys...