硅桥联茂金属催化1-癸烯聚合的研究

用硅桥联茂金属催化体系rac-Me_2Si(1-Ind)_2ZrCl_2/Al(i-Bu)_3/Me_2NHPh]~+B(C_6F_5)_4]~-催化1-癸烯聚合,考察了茂金属浓度、Al/Zr摩尔比、B/Zr摩尔比、反应温度、反应时间对聚合产物性能的影响。结果表明:在Zr/1-癸烯摩尔比为4×10~(-5)、Al/Zr摩尔比为80、B/Zr摩尔比为1.2、反应温度为80℃、反应时间为1h的条件下,1-癸烯的转化率达到97.6%,运动黏度(100℃)为599.4mm~2/s,黏度指数为285,倾点为-26℃,数均相对分子质量为12 608,相对分子质量分布为1.86。同时结合聚合反应机理和催化剂微观构型,对比分析了硅桥联茂金属催化体系rac-Me_2Si(1-Ind)_2ZrCl_2/Al(i-Bu)_3/Me_2NHPh]~+B(C_6F_5)_4]~-与亚乙基桥联茂金属催化体系rac-Et(1-Ind)_2ZrCl_2/Al(i-Bu)_3/Me_2NHPh]~+B(C_6F_5)4]~-在催化1-癸烯聚合方面的不同表现,表明无论是从催化剂的活性还是从产物相对分子质量来看,硅桥联茂金属催化剂的性能明显优于亚乙基桥联催化剂。最后釆用全自动反应量热仪进行放大反应,得到此反应的聚合反应热为61.8kJ/mol。

POLYMERIZATION OF 1-DECENE CATALYZED BY SILICON-BRIDGED METALLOCENE

Polymerization of 1-decene catalyzed by silicon-bridged metallocene catalyst system rac-Me2Si(1-Ind)2ZrCl2/Al(i-Bu)3/Me2NHPh]+B(C6F5)4]- was studied. The effects of the concentration of metallocene catalyst, molar ratio of Al to Zr, molar ratio of boron (B) to Zr, reaction temperature and reaction time on polymer properties were investigated. The results show that at molar ratio of Zr to 1-decene 4×10-5, molar ratio of Al to Zr 80, molar ratio of B to Zr 1.2, reaction temperature 80 ℃and reaction time 1 h, the conversion of 1-decene reaches 97.6% and the kinematic viscosity (100 ℃) is 599.4 mm2/s, the viscosity index(VI) is 285, the number-average molecular weight (Mn) is 12 608, and the molecular weight distribution is 1.87. Meanwhile, we analyzed the different performances of ethenylidene-bridged metallocene catalyst system (rac-Et(1-Ind)2ZrCl2/Al(i-Bu)3/Me2NHPh]+B(C6F5)4]-) and rac-Me2Si(1-Ind)2ZrCl2/Al(i-Bu)3/Me2NHPh]+B(C6F5)4]- in terms of catalytic polymerization of 1-decene based on polymerization mechanism and catalyst micro configurations. The results both from the activity of catalyst and from the product molecular weight indicate that the silicon-bridged metallocene catalyst system is better. Finally, automatic reaction calorimeter was used to analyze the reaction under scale–up conditions, and found that the polymerization reaction heat is 61. 8 kJ/mol.