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将rac Me2 Si(Ind) 2 ZrCl2 与甲基铝氧烷 (MAO)预络合后负载于SiO2 上得到了高活性的负载型茂金属催化剂 ,并用于丙烯等规聚合 ,研究了 [Al]/ [Zr]比、聚合温度对聚合活性、产物分子量、聚合动力学的影响 ,同时与相应的均相体系进行比较 .结果表明 ,负载化后 ,活性中心的稳定性提高 ,所得聚合物的分子量也明显高于均相体系 .同时用13 C NMR测定了两种催化体系所制备的等规聚丙烯的微结构 .结果发现 ,负载型茂金属催化剂制得的聚丙烯立构选择性高于均相体系 ,其五元组立构序列 [mmmm]从均相的 82 0 %提高到负载的 86 3 % .同时区域选择性也有所改进 ,2 ,1 插入、1 ,3 插入分别从均相体系的 4 4‰和 1 9‰降到负载体系的 3 7‰和 0 5‰ .
The preactivated complex of rac Me2 Si (Ind) 2 ZrCl2 with methylaluminoxane (MAO) was supported on SiO2 to obtain a highly active supported metallocene catalyst for isotactic polymerization of propylene. The effects of [Al] / [Zr] ratio, the polymerization temperature on the polymerization activity, product molecular weight, polymerization kinetics, and at the same time with the corresponding homogeneous system.The results show that after loading, the stability of the active center increased, the molecular weight of the resulting polymer also Was significantly higher than the homogeneous system.At the same time by 13 C NMR determination of the two catalytic systems prepared isotactic polypropylene microstructure.The results showed that the supported metallocene catalyst polypropylene prepared higher stereoselectivity than homogeneous System, the five-tuple [mmmm] increased from 82 0% to 86 3% of the load, while the regioselectivity was also improved. The insertion of 2 and 1, and the insertion of 1 and 3 from the homogeneous system 4 4 ‰ and 1 9 ‰ to 3 7 ‰ and 0 5 ‰ of the load system.