Propylene Polymerization Performance of Isolated and Aggregated Ti Species Studied Using a Well-Designed TiCl3/MgCl2 Ziegler-Natta Model Catalyst
✍ Scribed by Toru Wada; Toshiaki Taniike; Iku Kouzai; Shougo Takahashi; Minoru Terano
- Publisher
- John Wiley and Sons
- Year
- 2009
- Tongue
- English
- Weight
- 191 KB
- Volume
- 30
- Category
- Article
- ISSN
- 1022-1336
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✦ Synopsis
Abstract
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.
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