The supported catalysts for propylene polymerization were prepared by milling Mg （OEt）2 with EB （ethylbenzoate） and treating with TiCl4 solution. When TiCl4/（Mg（OEt）2/EB） （mol.） ratio was increased, decrease in contents of-OEt and Ti of the catalysts was observed, while the content of EB increased. It is proved by analyses of IR, X-ray and XPS that during co-milling Mg（OEt）2 with EB no reactions have taken place. But after treatment with TiCl4 solution, Mg（OEt）2 converts into MgCl2 and EB coordinates on the resulting MgCl2 carrier, a surface complex forms.The activity of catalysts,isotacticity and vicosimetric molecular weight of polypropylene increase with the decrease of the content of ethoxyl group. The kinetic curves of propene polymerization obtained with present catalysts system display decay curves. It is found from the triad tacticity calculated from the expanded spectra of methyl carbon region that, ethoxyl group in catalyst has an effect on the configuration of polymer chain.
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