POLYMERIZATION OF PROPYLENE USING SUPPORTED, CHIRAL, ANSA-METALLOCENE CATALYSTS - PRODUCTION OF POLYPROPYLENE WITH NARROW MOLECULAR-WEIGHT DISTRIBUTIONS

The chiral ansa-metallocenes 1,2-ethylenebis(eta(5)-1-indenyl)- and 1,2-ethylenebis(eta(5)-1-tetrahydroindenyl)zirconium dichloride (1 and 2, respectively) can be supported on partially dehydroxylated SiO2 and Al2O3, and these supported systems can be used to polymerize propylene in the presence of methylaluminoxane. The most active supported systems were derived from partially dehydroxylated SiO2 or Al2O3 that had been pretreated with excess trimethylaluminum. The properties of the polypropylene produced are essentially indistinguishable from that produced under homogeneous conditions using these same catalysts.