从烯胺中对极性单体插入聚合物的机械洞察力
Tobias Friedberger1, Philipp Wucher, Stefan Mecking
1Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, Universitätsstrasse 10, 78457 Konstanz, Germany.
Journal of the American Chemical Society
|January 5, 2012
概括
这项研究表明,极性添加剂显著抑制了N-异烯酸胺 (NIPAM) 和相关单体与乙烯的催化共聚化. 抑制的程度因添加剂而异.
科学领域:
- 有机金属化学 有机金属化学
- 聚合物化学 聚合物化学
- 催化剂是一种催化剂.
背景情况:
- 复合物是烯聚合和共聚合的有效催化剂.
- 烯胺单体在聚合过程中存在独特的挑战,原因是它们的极性胺组.
- 了解单体插入机制和催化剂抑制对于控制聚合物特性至关重要.
研究的目的:
- 使用催化剂研究N-异烯酸 (NIPAM),N,N-二甲基烯酸 (DMAA) 和2-乙胺乙烯酸 (AcAMEA) 与乙烯的共聚化.
- 阐明极性添加剂在抑制聚合过程中的作用.
- 为了确定不同烯胺单体的插入区域选择性和动力学,在甲基键.
主要方法:
- 使用特定的催化剂前体,P^O) PdMe (DMSO) 的共聚化反应.
- 使用各种非可聚合的极性添加剂进行抑制研究,以量化减速效应.
- 通过确定单体插入的伪第一阶速率常数来进行动力分析.
- 使用电喷离子质谱法 (ESI-MS) 和单晶X射线衍射的反应产品的结构特征.
主要成果:
- 自由氨基基基组对中心的可逆kappa-O-协调显著延迟了聚合.
- 聚合抑制随着添加剂的极性而增加,DMSO导致最显著的延迟.
- 单体插入率按照DMAA < AcAMEA < NIPAM < 甲基烯酸盐的顺序进行.
- 确定了NIPAM的连续插入产品以及DMAA的2,1和1,2插入产品,并对其进行了结构性特征.
结论:
- 烯胺与乙烯的催化共聚化对极性功能组敏感,导致催化剂抑制.
- 胺组与中心的协调在调节聚合动力学方面发挥着至关重要的作用.
- 了解这些相互作用可以更好地控制聚合过程和设计新型聚合物架构.
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