BCZ催化剂对外给电子体的响应研究

Studies on Response of BCZ Catalyst in Propylene Polymerization to External Electron Donors

分别以四乙氧基硅烷(TEOS)、二环戊基二甲氧基硅烷(DCPDMS)及复配的TEOS/DCPDMS为外给电子体,考察了BCZ催化剂的聚合性能及所得聚丙烯的熔体流动速率(MFR)和等规度。实验结果表明,TEOS为外给电子体时BCZ催化剂的氢调敏感性较好,而DCPDMS为外给电子体所得聚丙烯的等规性能较好;通过调节BCZ催化剂中TEOS/DCPDMS的配比,可在一定范围内调节聚丙烯的等规度和MFR,当n(TEOS)∶n(DCPDMS)=90∶10时,可制得MFR(10min)为49.1 g、等规度为95.6%的聚丙烯;采用TEOS/DCPDMS复配外给电子体时,BCZ催化剂可在较高的聚合温度下制备MFR和等规度均较高的聚丙烯产品。

The properties of BCZ catalyst with tetraethoxysilane（TEOS）, dicyclopentyl dimethoxy silane（DCPDMS） or composite TEOS/DCPDMS as the external electron donors, and the melt flow rate（MFR）and isotacticity of the polypropylene prepared with the catalyst were studied. The results indicated that TEOS had fairly good hydrogen sensitivity while DCPDMS showed better stereoselectivity. By adjusting the ratio of TEOS to DCPDMS for the BCZ catalyst, the MFR and isotacticity of the polypropylene can be regulated in a certain range. When n（TEOS） ： n（DCPDMS） 90 ： 10, the polypropylene with MFR（10 min） of 49.1 g and i sotacticity of 95.6% can be obtained. With DCPDMS/TEOS as the composite extemal electron donors, the BCZ catalyst can be used in preparing polypropylene with both high MFR and high isotacticity.