摘要: (CpCH2CH2CH = CH2)2MCl2(M=Zr, Hf)/MAO and Cp2ZrCl2/MAO (Cp=cyclopentadienyl; MAO=methylaluminoxane) catalyst systems have been compared for ethylene copolymerization to investigate the influence of theligand and transition metal on the polymerization activity and copolymer properties. For both CH2CH2CH=CH2 substitutedcatalysts the catalytic activity decreased with increasing propene concentration in the feed. The activity of the hafnocenecatalyst was 6～8 times lower than that of the analogous zirconocene catalyst,13C NMR analysis showed that the copolymer obtained using the unsubstituted catalyst Cp2ZrCl2 has greater incorporatiec of propene than those produced by CH2CH2CH=CH2 substituted Zr and Hf catalysts. The melting point, crystallinity and the vicosity-average molecular weight of the copolymer decreased with an increase of propene concentration in the feed. Both CH2CH2CH=CH2 substituted ZR and Hf catalysts exhibit little or no difference in the melting point and crystallinity of produced copolymers.However, there are significant differences between the two zirconocene catalysts. The copolymer produced by Cp2ZrCl catalyst have much lower Tm and Xc than those obtained with the (CpCH2CH2CH=CH2)2ZrCl2 catalyst. The density and molecular weight of the copolymer decreased inthe order: (CpCH2CH2CH=CH2)2HfCl2>(CpCH2CH2CH=CH2)2HfCl2 in ethylene/propene copolymerization and compared the results with those obtained with unsubstituted Cp2ZrCl2 catalyst.