Amidinate-Based Catalysts for Stereoselective Living Ziegler-Natta Polymerizations

摘要

The intimate relationship between polyolefin stereochemical microstructure and polymer physical properties has spurred the development of new classes of homogeneous Ziegler-Natta catalysts that can effect a high degree of stereocontrol in the polymerization of alpha-olefins.To date,efforts with catalysts possessing constrained geometries(e.g.,ansa-bridged metallocenes)have now resulted in the production of systems capable of providing a wide range of microstructures,including isotactic,syndiotactic and hemiisotactic.