Depelopment of supported catalysts for living polymerization of olefins and its application to gas-phse polymerization

负载型烯烃活性聚合催化剂的研制及其在气相聚合中的应用

基本信息

批准号：
15360419
负责人：
SHIONO Takeshi
金额：
$ 6.66万
依托单位：
HIROSHIMA UNIVERSITY (2004-2005)Tokyo Institute of Technology (2003)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

项目摘要

The living polymerization, therefore, has attracted much attention and several papers have reported on the living polymerization of propene by homogeneous catalytic systems. There are, however, few examples for living polymerization of propene by supported single-site catalytic systems, which should be very important from the practical point of view. We have previously found that living polymerization of propene proceeded in heptane at 0℃ by a chelating (diamide) dimethyltitaniumcomplex (1) activated with trialkylaluminum-free modified methylaluminoxane (dMMAO), which is easily soluble in hydrocarbons.We prepared supported dMMAOs using silica gel, alumina and magnesia by the reaction of the support and dMMAO in heptane and conducted propene polymerization with 1 to clarify the supporting effects of dried MMAO. The supported systems conducted living polymerization of propene at 0℃ without any induction period regardless of the metal oxides for dried MMAO. The propagation rate constants (k_p) of these systems and the molecular weight distribution (M_w/M_n) of the produced polymer depended on the metal oxide employed. The k_p value increased with the increase in Lewis acidity of MMAO on the support and the broadening (M_w/M_n) was ascribed to the distribution of Lewis acidity caused by the heterogeneity of the supported cocatalyst. The systems gave atactic polypropylene regardless of the metal oxides for dried MMAO.We also conducted propene polymerization with ansa-fluorenylamidodimethyltitanium (2), which conducts living polymerization of propene when activated with dMMAO, in place of 1. Although the 2-supported dMMAO systems of silica-gel and alumina showed very high initial activity, the system deactivated and chain transfer also occurred. The results indicated that the combination of the complex and the supported activator was very important for the living polymerization with supported catalytic systems.

因此，生命聚合引起了很多关注，并报道了几篇关于均质催化系统对丙烯的生活聚合的报道。但是，很少有通过支持的单位催化系统对丙烯的生活聚合的例子，从实际的角度来看，这应该非常重要。我们先前已经发现，丙烯的生存聚合通过螯合（Dimide）Dimethyltitaniumcomplex（1）在0℃中进行，并用无试的Kylaminum-Firakylaminum修饰的甲基铝氧烷（DMMAO）激活，该甲基氧烷（DMMAO）易于在水中固体。七烷并用1进行丙烯聚合，以阐明干燥的MMAO的支撑作用。所支持的系统在0℃进行生存聚合时无诱导周期，而不管干燥的MMAO的金属氧化物如何。这些系统的传播速率常数（K_P）以及产生的聚合物的分子量分布（M_W/M_N）取决于金属氧化物的员工。 K_P值随着MMAO的Lewis酸度的增加而增加，并将扩展（M_W/M_N）分配到由支持的Cocatalyst的异质性引起的路易斯酸度的分布。该系统给出了均匀的聚丙烯，无论金属氧化物的干燥含量如何也发生了链转移。结果表明，复合物和受支持的激活剂的组合对于使用支持的催化系统的生活聚合非常重要。