【摘要】 在合成新型的碳桥联前过渡金属稀土异核茂金属化合物[(C5H5)MtCl2][(C5H4)CMe2(C9H6)][(C5H5)Sm Cl][Mt=Zr(5),Ti(7)]之后,经甲基铝氧烷活化催化乙烯聚合,考察了催化剂浓度、[Al]/[Cat]、温度、聚合时间对聚合反应的影响.与相应的单核茂金属相比,发现TiSm体系(7)的催化活性升高,而ZrSm体系(5)的活性有所下降;然而,随着时间的延长,前者所得的聚乙烯分子质量逐步下降,而后者所得的聚乙烯分子质量逐步上升.TiSm体系(7)与ZrSm体系(5)不同的催化性能也许与Sm和不同的前过渡金属间的组合有关.所得聚乙烯的GPC分析呈双峰,相对分子质量分布较宽(>3 00).更多还原

【Abstract】 It has been synthesized two new dinuclear metallocene complexes ,which were used for ethylene polymerization with MAO as cocatalyst. Detailed study on the effect of polymerization caused by catalyst concentration, molar ratio of /, temperature and time, showed that the catalytic activity of complex 7 is higher than that of the corresponding mononuclear metallocene of Cp₂TiCl₂, while the catalytic activity of complex 5 is lower than that of the corresponding mononuclear metallocene of Cp₂ZrCl₂; The molecular weight （M_η） of polyethylene produced by above two catalyst systems is somewhat decreased, and the molecular weight distribution （MWD） becomes broader. With prolongation of time, the molecular weight of polyethylene obtained by complex 7 decreases, while the molecular weight of polyethylene obtained by complex 5 increases.更多还原