Wada Toru, Taniike Toshiaki, Kouzai Iku, Takahashi Shougo, Terano Minoru
School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
Macromol Rapid Commun. 2009 Jun 2;30(11):887-91. doi: 10.1002/marc.200900015. Epub 2009 Mar 17.
In propylene polymerization with MgCl(2) -supported Ziegler-Natta catalysts, it is known that the reduction of TiCl(4) with alkylaluminum generates Ti(3+) active species, and at the same time, leads to the growth of TiCl(x) aggregates. In this study, the aggregation states of the Ti species were controlled by altering the Ti content in a TiCl(3) /MgCl(2) model catalyst prepared from a TiCl(3) · 3C(5) H(5) N complex. It is discovered that all the Ti species become isolated mononuclear with a highly aspecific feature below 0.1 wt.-% of the Ti content, and that the isolated aspecific Ti species are more efficiently converted into highly isospecific ones by the addition of donors than active sites in aggregated Ti species.
在使用氯化镁负载的齐格勒-纳塔催化剂进行丙烯聚合时，已知用烷基铝还原四氯化钛会生成三价钛活性物种，同时导致四氯化钛聚集体的生长。在本研究中，通过改变由三氯化钛·3C₅H₅N络合物制备的三氯化钛/氯化镁模型催化剂中的钛含量，来控制钛物种的聚集状态。研究发现，当钛含量低于0.1重量%时，所有钛物种均变为孤立的单核物种，具有高度非特异性特征，并且与聚集钛物种中的活性位点相比，通过添加给体，孤立的非特异性钛物种能更有效地转化为高度等规的物种。
