INFLUENCE OF INDENYL LIGAND SUBSTITUTION PATTERN ON METALLOCENE-CATALYZED PROPENE COPOLYMERIZATION WITH 1-OCTENE

Copolymerization of propene with 1-octene (1 mol/l mol) was performed in toluene at 40 degrees C in the presence of homogeneous methylalumin oxane (MAO)-activated ansa-metallocenes in order to study the role of benzannelation and 2-methyl-substitution of the silylene-bridged bisin denyl ligand on comonomer incoporation, molecular mass, molecular mass distribution, and end groups. While 2-methyl-substitution promoted hi gher degree of polymerization without affecting copolymerization param eters, benzannelation improved markedly 1-octene incorporation. Only w ith MAO-activated rac-Me2Si(2-MeBenz[e]Ind)(2)ZrCl2 catalysts vinylide ne end groups were formed exclusively. Molecular weight distribution r emains narrow in all experiments.