Ethylene and α-olefin copolymerization by bimetallic zirconium catalysts

Abstract

It has been previously demonstrated that bimetallic complexes supported by phenoxy-imine and bisphenoxy amine ligands can be used for ethylene and α-olefin polymn. with enhanced tolerance of amines, copolymn. with amino olefins, and improved tacticity control. An expanded series of bimetallic Zr polymn. catalysts based on rigid para- and meta-terphenyl linkers has been synthesized and characterized by a variety of spectroscopic techniques. The activity and comonomer incorporation of this series of catalysts in the copolymn. of ethylene and a range of α- olefins is examd. and discussed with regards to ligand sterics and electronics and in comparison to the related series of monozirconium control catalysts. The polymn. mechanism of these monomers will also be discussed.