The effect of alcohol treatment in the preparation of MgCl 2 support by a recrystallization method on the catalytic activity and isotactic index for propylene polymerization

Abstract

An MgCl 2 catalyst support for propylene polymerization was prepared by dissolving MgCl 2 in ethanol and/or l-propanol and recrystallizing it in an n-decane medium with vacuum drying. This support was modified by adding di- n-butyl phthalate as an internal electron donor, and subsequently TiCl 4 was impregnated on the modified support. The prepared support and the catalyst were characterized by GC, HPLC, SEM, and N 2-BET surface analyser. Propylene was polymerized with the catalyst and triethyl-aluminium in the presence or absence of ethyl benzoate, and the effect of alcohol treatment on the catalytic activity and isotactic index (I.I.) was examined. It was found that the propanol-treated catalyst showed a better performance than the ethanol-treated catalyst, owing to different amounts of remaining organic compounds. When the amounts of remaining alcohols were the same, it was also revealed that propanol was effective in enhancing the I.I. and ethanol was effective in enhancing the catalytic activity.