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在SiO2载体中引入分子状态的MgCl2后再负载TiCl4,制备了高活性的用于乙烯与1-己烯淤浆共聚的双载体Ziegler-Natta催化剂TiCl4/SiO2-MgCl2。催化剂的最佳制备条件:n(TiCl4)∶n(MgCl2)=10,滴加TiCl4温度为-25℃,n(C2H5OH)∶n(MgCl2)=2.4,m(SiO2)∶m(MgCl2)=1。用激光粒度分析仪、SEM和WAXD等手段对催化剂的粒径分布、颗粒形态和结晶情况进行表征的结果显示,催化剂的粒径在20～45μm之间,较均匀;且颗粒形态呈球形。当催化剂中Ti的质量分数为5.1%时,该催化剂可高效催化乙烯与1-己烯进行淤浆共聚,催化效率达1.59kg/g,乙烯-1-己烯共聚物的数均相对分子质量为3.1×104g/mol,相对分子质量分布为16.3,呈宽分布。
TiCl4 / SiO2-MgCl2 was prepared by introducing MgCl2 into the SiO2 support and then TiCl4 to prepare a highly active dual carrier Ziegler-Natta catalyst for the copolymerization of ethylene with 1-hexene. The optimum conditions for the preparation of catalyst are as follows: n (TiCl4): n (MgCl2) = 10, the temperature of TiCl4 added dropwise is -25 ℃, the molar ratio of n (C2H5OH) 1. The particle size distribution, particle morphology and crystallization of the catalyst were characterized by means of laser particle size analyzer, SEM and WAXD. The results show that the catalyst particle size is 20 ~ 45μm, more uniform; and the particle morphology is spherical. When the mass fraction of Ti in the catalyst is 5.1%, the catalyst can efficiently catalyze the slurry copolymerization of ethylene and 1-hexene with a catalytic efficiency of 1.59 kg / g, a number-average molecular weight of the ethylene-1-hexene copolymer 3.1 × 104g / mol, the relative molecular mass distribution of 16.3, showing a wide distribution.