Propene polymerization catalyzed over MCM-41 and VPI-5-supported Et(ind)(2)ZrCl2 catalysts

Abstract

Et(ind)(2)ZrCl2 (C2H5(indenyl)(2)ZrCl2) confined inside regular pores of molecular sieves MCM-41 and VPI-5 were prepared and used to polymerize propene with high activity. Stereoregularity, melting point and molecular weight of polypropene obtained were increased and the polymerization behavior was quite different from that prepared with homogeneous Et(ind)(2)ZrCl2. The small, regular and cylindrical pores of MCM-41 and VPI-5 suppress the formation of inactive binuclear complexes between metallocene and metallocene, or between metallocene and methylaluminoxane, resulting in stable active sites and high activity in propene polymerization.