一个固态扩展的"受约束几何学催化剂"用于高度活跃的烯酸聚合和共聚合:一个不屈不的comonomer效应
Levi J Irwin1, Joseph H Reibenspies, Stephen A Miller
1Department of Chemistry, Texas A&M University, College Station, TX 77843-3255, USA.
Journal of the American Chemical Society
|December 23, 2004
概括
一种新型的约束几何学催化剂,含有八甲基甲基化二二部分,对α-olefins具有很高的反应性. 这种催化剂,当与甲基氨酸 (MAO) 激活时,显示出与乙烯共聚合物中的共聚物度成比例的活性.
科学领域:
- 有机金属化学 有机金属化学
- 聚合物科学 聚合物科学
- 催化剂是一种催化剂.
背景情况:
- 约束几何学催化剂 (CGCs) 在烯聚合过程中至关重要.
- 金属中心周围的绝缘体积影响催化剂活性和聚合物特性.
- 结合庞大的配体可以提高催化剂性能.
研究的目的:
- 为了合成和描述一个包含14A octamethyloctahydrodibenzofluorene部分的固态扩展的CGC.
- 评估新催化剂 (1) 在烯聚合中的催化活性,特别是对α-olefins的催化活性.
- 为了研究催化剂与乙烯和更高的α-olefins的共聚合行为.
主要方法:
- 合成受约束几何学催化剂Me2Si (((eta1-C29H36) (((eta1-N-tBu) ZrCl2.OEt2 (1).
- 催化剂的固态结构分析.
- 使用催化剂激活甲基氨酸 (MAO) 的olefin聚合和共聚合实验.
- 聚合活动的动态分析.
主要成果:
- 催化剂 (1) 的固态结构表明了显著的空间可访问性.
- 催化剂 (1) /MAO对α-olefins表现出异常的反应性,超过对乙烯的反应性.
- 与乙烯共聚的活性与4-甲基-1-或1-烯的度线性且连续成正比.
结论:
- 固态扩展的连接体设计提高了催化剂的可访问性和反应性.
- 催化剂对比乙烯更高的α-olefins具有选择性的反应性.
- 活动和共纳米度之间的观察到的线性关系为共聚合动力学提供了洞察力.
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