ZrCl4 as Catalyst for Olefins and Styrene Polymerization: Effect of Ethereal Donors on the Activity and Stereospecificity

Complexes of ZrCl4 incorporating neutral donors such as THF and Et2O activated by methylaluminoxane have been found to be active homogeneous catalytic systems for the polymerization of ethylene. They also promote the propylene and styrene polymerization with high degree of iso- and syndiotacticity, respectively. The different behaviors in propylene and styrene polymerization using methylalumoxane containing different amounts of Al(CH3)(3) with respect to isotactic propylene and syndiotactic styrene polymerization of these compounds suggest that the presence of neutral Lewis bases on the metal center plays a crucial role on the stereoselectivity of polymerization reaction.