Study On The Internal Electron Donor In A Novel Catalyst For Propylene Polymerization

This paper established synthetical processes of a novel internal electron donor with ether bonds and ester bond-2-monoethyl succinyl-9,9-bis(methoxymethyl)fluorene by molecular designing. Four intermediate products were synthesized involving etherification, esterification and Frieded-Crafts acylation, which fluorine, paraformaldehyde and sodium ethoxide etc. were used as primary raw materials. Their names were 9,9-bis(hydromethyl)fluorene, 9,9-bis(methomethyl)fluorene, monoethyl succinate and monoethyl succinyl chloride. Finally 2-monoethyl succinyl-9,9-bis(methoxymethyl)fluorene was synthesized success- fully. At the same time, a series of reaction factors such as material proportion, catalyst dosage, reaction time and temperature were investigated, which influenced the reactions. Then the optimum reaction conditions were obtained by orthogonal experiment, and FT-IR, 1H-NMR and 13C-NMR spectrum were utilized to analyze and characterize the configuration of the four intermediate products and the final product. In the end, first MgCl2/C2H5OH carrier was synthesized, which used magnesium chloride, ethanol and titanium tetrachloride as raw materials, second the novel catalyst for propylene polymerization was synthesized by using 2-monoethyl succinyl-9,9-bis(methoxymethyl) fluorene as the internal electron donor. The morphology of catalyst particles was spherical. The content of titanium was 2.39%. Then propylene bulk polymerization was used to evaluate the performance of the catalyst. The activity of the catalyst was 1.48×106gPP/gTi and the isotacticity was 85.3% without the external electron donor. And the activity of the catalyst was 1.37×106gPP/gTi and the isotacticity was 90.7% when cyclohexylmethyl-dimethoxysilane was added as the external electron donor.