过渡金属甲基基氧 (PHENI*) 复合物的结构和乙烯聚合反应的趋势
Clement G Collins Rice1, Justin A Hayden1, Adam D Hawkins1
1Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12 Mansfield Road, Oxford OX1 3TA, U.K.
新的甲基基氧 (PHENI*) 催化剂在乙烯聚合方面表现出异常活力,产生超高分子量聚乙烯 (UHMWPE),具有更好的金属可访问性和催化效率.
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:
- 一个新型的ansa-permethylindenyl-phenoxy (PHENI*) 过渡金属化物复合物的合成和表征.
- 探索连接物交换反应,以与各种辅助连接物形成多种PHENI*复合体.
研究的目的:
- 在乙烯聚合过程中研究PHENI*复合物的结构性质和催化性能.
- 将PHENI*催化剂的活性和选择性与现有的PHENICS催化剂进行比较.
主要方法:
- 合成和表征PHENI*复合物 (M = Ti,Zr,Hf) 的不同替代剂.
- 固态晶体结构分析以确定首选的形状和金属可访问性.
- PHENI*复合物的异质化在固体聚甲基氨酸 (sMAO) 上,用于乙烯聚合研究.
- 研究催化剂-共催化剂离子配对效应和辅助联体影响在均和泥相聚合物中.
主要成果:
- 晶体结构显示了两种首选的构造,其中甲基丁联体有利于金属的可访问性,而非丁联体.
- 异质化PHENI*复合物表现出异常的乙烯聚合催化活性,超过了PHENICS催化剂.
- 实现了超高分子量聚乙烯 (UHMWPE) 的形成.
- 催化剂-共催化剂离子配对和辅助联体离开组显著影响催化性能.
- 催化效率和聚乙烯分子量随着压力而增加.
结论:
- PHENI* 催化剂是UHMWPE受控合成的高度活性类别.
- PHENI* 配体的结构特征有助于增强催化性能.
- 这些发现为开发先进的烯酸聚合催化剂提供了途径.
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