MAGNESIUM DICHLORIDE SUPPORTED TITANIUM CATALYST SYSTEM - DIMETHOXYPROPANE AS AN EXTERNAL LEWIS BASE

Supported titanium catalyst was prepared by the reaction of magnesium dichloride-bispentanol with titanium tetrachloride and dibutyl phthalate followed by the treatment of the product with titanium tetrachloride. The intermediate products and the catalyst were characterized by compositional analysis, surface area and X-ray diffraction measurements. The activity of the catalyst was examined for propylene polymerization using triethylaluminium as cocatalyst and/or dimethoxypropane as an external Lewis base. The effect of dimethoxypropane on the activity and stereospecificity of the catalyst was compared with the analogous silicon compound-dimethyldimethoxysilane. The catalyst shows higher isospecificity in the presence of dimethoxypropane than dimethyldimethoxysilane.