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出 处:《Journal of Wuhan University of Technology(Materials Science)》2007年第4期667-672,共6页武汉理工大学学报(材料科学英文版)
基 金:the National Natural Science Foundation of China(20374043);SINOPEC(X501025)
摘 要:Ansa-Cyclohexyl-bis(4,5,6,7-tertrahydro-l-indenyl) zirconium dichloride (5) was used as catalyst for propylene and ethylene polymerization together with methyl aluminoxane (MAO) as the cocatalyst. Isotactic polypropylene (PP) was obtained with the highest activity of 6.37× 107g PP (molZr)^-1h^-1. The mesomeso (mmmmm) pentads sequence content of PP was determined by 13C NMR spectroscopy. The dependence of the microstructure on the reaction temperature and the AI/Zr molar ratio was examined and the catalytic activity of complex 5 was compared with that of the similar ansa-zirconocene 3. The high activity of the new zirconocene 5 for propylene isospectic polymerization at high temperature (60℃) is the result of its unique bridged-group structure. Complex 5/MAO displays also high catalytic activity of 0.46× 10^6 to 9.87× 10^6g PE(molZr)^-h^-in the homo-polymerization of ethylene, The visometric molecular weight of PE ranges from 0.97×10^4 to 11.16×10^4 g.mol^- under the given conditions.^13C NMR spectroscopy analysis proves the PE to be linear polyethylene (LPE).Ansa-Cyclohexyl-bis(4,5,6,7-tertrahydro-l-indenyl) zirconium dichloride (5) was used as catalyst for propylene and ethylene polymerization together with methyl aluminoxane (MAO) as the cocatalyst. Isotactic polypropylene (PP) was obtained with the highest activity of 6.37× 107g PP (molZr)^-1h^-1. The mesomeso (mmmmm) pentads sequence content of PP was determined by 13C NMR spectroscopy. The dependence of the microstructure on the reaction temperature and the AI/Zr molar ratio was examined and the catalytic activity of complex 5 was compared with that of the similar ansa-zirconocene 3. The high activity of the new zirconocene 5 for propylene isospectic polymerization at high temperature (60℃) is the result of its unique bridged-group structure. Complex 5/MAO displays also high catalytic activity of 0.46× 10^6 to 9.87× 10^6g PE(molZr)^-h^-in the homo-polymerization of ethylene, The visometric molecular weight of PE ranges from 0.97×10^4 to 11.16×10^4 g.mol^- under the given conditions.^13C NMR spectroscopy analysis proves the PE to be linear polyethylene (LPE).
关 键 词:ANSA-ZIRCONOCENE propylene polymerization isotactic polypropylene ethylene polymerization
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