ZHONG Chifeng, GAO Mingzhi, MAO Bingquan. STUDY ON TiCl4/MgCl2 CATALYSTS FOR PROPYLENE POLYMERIZATION ——THE FUNCTIONS OF THE INTERNAL DONORS IN CATALYST SYSTEMS[J]. Acta Polymerica Sinica, 2003,(2):266-271.
ZHONG Chifeng, GAO Mingzhi, MAO Bingquan. STUDY ON TiCl4/MgCl2 CATALYSTS FOR PROPYLENE POLYMERIZATION ——THE FUNCTIONS OF THE INTERNAL DONORS IN CATALYST SYSTEMS[J]. Acta Polymerica Sinica, 2003,(2):266-271.DOI:
which contain free donor or different internal donors such as diisobutyl phthalate (DIBP) and 9
9-bis(methoxymethyl) fluorine (BMMF).The performances of propylene polymerization without external donors in catalyst systems were studied.Poly(propylene)s have been characterized by using gel permeation chromatography (GPC)
crystallization fractionation analysis (CRASTAF) and 13C-NMR analysis.It was found that the catalyst with BMMF as the internal donor resulted in polypropylene of best tacticity.It suggests that the internal donors have important influence on polymer tacticity.The polymerization was performed in the presence of different cocatalysts—Et3Al and i-Bu3Al.It was found that the microstructure of polymers obtained with catalyst BMMF (i-Bu3 Al/Ti=300) was as same as that obtained with catalyst DIBP (Et3 Al/Ti=50).It indicated that the stereoselectivity of the active site depended on the strength of donor coordination.