Precise Active Site Analysis for TiCl3/MgCl2 Ziegler-Natta Model Catalyst Based on Fractionation and Statistical Methods
Precise Active Site Analysis for TiCl3/MgCl2 Ziegler-Natta Model Catalyst Based on Fractionation and Statistical Methods
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DOI：
10.3390/catal3010137
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发表时间：
2013-02
期刊：
影响因子：
3.9
通讯作者：
Shougo Takahashi;Toru Wada;Toshiaki Taniike;M. Terano
中科院分区：
文献类型：
--
作者：
Shougo Takahashi;Toru Wada;Toshiaki Taniike;M. Terano
In heterogeneous Ziegler-Natta catalysts for olefin polymerization, isolation of a single type of active sites is a kind of ambition, which would solve long-standing questions on the relationship between active site and polymer structures. In this paper, polypropylene produced by TiCl3/MgCl2 model catalysts with minimum Ti heterogeneity was analyzed by combined solvent fractionation and the two-site statistical model. We found that the active sites of the model catalysts were classified into only three types, whose proportions were dependent on the Ti dispersion state. The addition of external donors not only newly formed highly isospecific sites, but also altered the stereochemical nature of the other active sites.
