近年来线型低密度聚乙烯(LLDPE)发展十分迅速.制造方法有气相法、溶液法等,气相法中以美国Union Carbide公司的Unipol技术最为重要.该公司早期的LLDPE专利采用铬系催化剂,近年来转向以四氢呋喃(THF)等给电子体改性的钛镁催化剂.与未改性的钛镁催化剂相比,其催化活性高,使乙烯与α-烯烃共聚的能力强,并易于调节分子量.显然,THF对改进催化剂的性能起了重要作用.关于MgCl_2/ In recent years, the linear low density polyethylene (LLDPE) is developing very rapidly. The manufacturing method is the gas phase method, the solution method, the gas phase method in the United States Union Carbide’s Unipol technology is most important.The company’s early LLDPE patents chromium-based catalyst, In recent years, it has turned to titanium-magnesium catalysts modified with electron donors such as tetrahydrofuran (THF), which has high catalytic activity compared with the unmodified titanium-magnesium catalyst, high ability of copolymerizing ethylene and α-olefin, and easy adjustment of molecular weight Clearly, THF plays an important role in improving the performance of the catalyst. Regarding the MgCl 2 /