Immobilization of Metallocenes through Noncovalent Bonding via MAO to a Reversibly Cross-Linked Polystyrene

Abstract

A novel catalyst system is presented on the basis of a reversibly cross-linked polystyrene support bearing nucleophilic functionalities such as ether bridges. The metallocene is bound noncovalently to the supporting polymer, avoiding a polymer analogous metallocene synthesis. A reversible cross-linking allows the fragmentation of the support during the polymerization process. Propene polymerization with supported Me 2 Si(2-MeBenzInd) 2 ZrCl 2 yields spherical polypropene beads with a diameter of about 1 mm, high melting points, high molecular weights, and narrow weight distributions. The properties, especially the tacticity, are similar to homogeneously polymerized propene, and the productivities of up to 8000 kg PP/(mol Zr h bar) are comparably high.