Application of porous inorganic materials to adsorptive separation of methylalumoxane used as co-catalyst in olefin polymerization

Inorganic siliceous porous materials with different average pore diameters were applied to the adsorptive separation of methylalumoxane (MAO) used as co-catalyst in α-olefin polymerization. The co-catalytic performance of the separated MAO was investigated by propylene polymerization with rac-ethylene(bisindenyl)zirconium dichloride (rac-Et(Ind)2ZrCl2). The polymerization activity and the stereoregularity of the resulting polymer were markedly dependent upon the pore size of the porous material used for adsorptive separation. From the results obtained by the solvent extraction of the produced polymers, it was suggested that the adsorptive separation of MAO by porous materials is helpful in the characterization of MAO, and at least two different species of MAO are present.