Synthesis of metallocene catalysts supported on polyp-(silylene)phenylene derivatives for the application to olefin polymerizations

摘要

The polymeric Ind_2Si(C_6H_4)_n and Ind_2Si(C_6H_4)_2_m compounds (Ind=indenyl) were synthesized via the condensation reaction of bisindenyldichlorosilane and p-dilithiobenzene or p-dilithiobiphenyl, and the supported-type zirconocene catalysts were prepared by reacting them with zirconium tetrachloride. The content of zirconium in the catalysts is much higher than that in the metallocene catalysts supported by inorganic compounds. Polymerizations of ethene and propene were conducted with them using methylaluminoxane (MAO) or ordinary alkylaluminiums as cocatalysts and toluene as the solvent. The catalysts combined with MAO display very high activities especially for the ethene polymerization. From the polymerization at high temperatures, it was found that the active species are markedly stabilized, probably due to the rigid backbones of the carriers. The activity of the catalysts activated with ordinary alkylaluminiums is far less as compared with those activated with MAO.