中文摘要：

分别以MgF2和AlCl3掺杂的MgCl2醇合物为载体，制备了TiCl4负载Ziegler-Natta催化剂，采用广角X射线衍射（WAXD）表征了催化剂的结构．在MgCl2／TICl4负载催化剂的载体中掺杂MgF2使催化剂活性明显提高，但是对聚乙烯的相对分子质量分布影响不大．在载体中掺杂AlCl3的催化剂虽然活性略有下降，但聚乙烯的相对分子质量分布显著增宽（重均与数均分子质量之比从10．4增大到27．7）．以纯AlCl3为载体的TiCl4负载催化剂催化生成相对分子质量分布极宽的聚乙烯（重均与数均分子质量之比为55．2），而其催化活性为MgCl2／TiCl4负载催化剂的一半左右．

英文摘要：

Ti-based Ziegler-Natta catalysts supported on MgCl2 doped with MgF2 and AlCl3 were prepared by the reaction of MgCl2/MgF2-ethanol adduct or MgCl2/AlCl3-ethanol adduct with TiCla, and the effect of doping on the catalyst performance in ethylene polymerization was investigated. The catalyst structure was studied by wide-angle X ray diffraction （WAXD）. Doping MgF2 in the catalyst caused increase in activity, while the molecular weight distribution （MWD） of polyethylene was little affected as compared to catalyst based on 100% MgCl2 support. Catalysts based on AlCl3 doped MgCl2 support showed a slightly lower activity than the undoped catalyst, but the polydispersity of polyethylene markedly increased with increasing AlCl3 content （Mw/Mn, from 10. 4 to 27.7）. When pure AlCl3 was used as the support, polyethylene with very broad MWD （Mw/Mn = 55.2） was produced, though the activity was only half that of the MgCl2/TICl4 catalyst.