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采用反应法，将ＮｉＣｌ_２与ＴｉＣｌ_４负载于复合载体ＭｇＣｌ_２－ＳＯｆ_２上，制得新型双过渡金属催化体系ＴｉＣｌ_４－ＮｉＣｌ_２／ＭｇＣｌ_２－ＳｉＯ_２／Ａｌ（ｉ－Ｂｕ）_３．该催化剂用于乙烯气相聚合，当ｘ（Ｎｉ）为１２．５％时，催化剂效率最高，聚合动力学属衰减型．催化剂因含有镍化合物具有齐聚及原位共聚性能，得到的聚乙烯具有支化度为３．６～７．２支化数／１０００Ｃ的中密度聚乙烯，且产物相对分子质量增大。
A novel double-transition metal catalyst system TiCl 4 -NiCl 2 / MgCl 2 -SiO 2 / Al (i-Bu) _3 was prepared by reaction of NiCl_2 and TiCl_4 supported on the composite support MgCl_2-SOf_2. The catalyst is used for the gas phase polymerization of ethylene. When x (Ni) is 12.5%, the catalyst has the highest efficiency and the polymerization kinetics belongs to the decay type. Due to the catalyst containing nickel compounds with oligomerization and in-situ copolymerization properties, the resulting polyethylene has a degree of branching of 3.6 to 7.2 branches / 1000C of medium density polyethylene, and the relative molecular mass of the product increases.