内给电子体对Ziegler-Natta催化剂性能的影响

研究了5种新型内给电子体对Ziegler-Natta催化剂结构和催化性能的影响.结果表明,使用两种不同制备工艺制备的氯化镁载体均为δ晶型,而不同的内给电子体的加入使得催化剂的氯化镁载体具有不同的微晶结构和形态.在催化剂制备阶段中,内给电子体的加入方式对催化剂的性能有很大的影响.在5种内给电子体中,以cis-1,2-环己二甲酸二异丁酯为内给电子体时,催化剂的聚合活性和PP等规度最高,性能与工业催化剂相当;当选用cis-1,2-环己二甲酸二异丁酯为内给电子体,CMMS为外给电子体,硅钛物质的量之比为10及铝钛物质的量之比为100时,催化剂的聚合活性和PP等规度达到最高.

ZIEGLER-NATTA CATALYSTS WITH INTERNAL ELECTRON DONORS

Several diesters were developed as internal donors of the Ziegler-Natta catalysts,the molecular structures of the diesters are close to that of diisobutyl phthalate.Furthermore,the effects on the performance of the catalysts were studied.Results showed that the catalysts prepared by different preparation processes have the same MgCl2 lattice style(δ).The changing of diesters have notable influences on the porosity and the specific surface areas of the catalysts,and the polymerization performance and the PP isotactic index vary with different addition ways of the diesters in the preparation processes of the catalysts.When the internal donor is diisobutyl cis-cyclohexane dicarboxylate,the polymerization activity of the catalyst and the PP index are the highest,reaching the level of the industry catalyst.In the polymerization of CAT-2A,using CMMS as the external electron donor,the ratio of Si to Ti is 10 and the ratio of Al to Ti is 100,the polymerization activity and PP isotactic index reach the highest level.