阳离子结合物添加二氧化碳/丁二烯衍生乳的寡合化
Brennan J Crawford1, Calum Bochenek2, Luis D Garcia Espinosa1
1School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325-3909, United States.
ACS macro letters
|May 15, 2024
概括
新的有机催化剂,包括和disilazanes,使不和乳的有效的阳离子寡合,提供对聚合物微观结构和热性质的控制.
科学领域:
- 聚合物化学 聚合物化学
- 有机合成 有机合成
- 催化剂是一种催化剂.
背景情况:
- 阳离子寡合化是一种关键的聚合技术.
- 不和乳是用于聚合物合成的多功能单体.
- 有机催化剂为传统金属催化剂提供了一个可持续的替代方案.
研究的目的:
- 通过使用各种核爱和非核爱基来研究不和 δ-瓦莱洛拉克顿的阳离子寡合化.
- 为了比较新型有机催化剂的疗效与如TBD这样的既有器官催化剂.
- 了解催化剂选择和反应条件如何影响聚合物微观结构和特性.
主要方法:
- 无离子寡合化反应在散装和溶液中.
- 使用瓜尼丁,disilazanes,phosphazenes和NaHMDS进行催化.
- 通过NMR,FTIR,MALDI-MS,MS/MS和IM-MS进行产品表征.
- 使用差分扫描热量计 (DSC) 进行热量分析.
- 使用尺寸排除色谱 (SEC) 确定分子重量.
主要成果:
- 与TBD相比,新型基质,特别是酸,表现出更高的生产力和活动.
- 实现了完全的单体转换,周转频率高达382h-1.1.
- 催化剂负载低至1mol%在室温下有效.
- 观察到微观结构的差异,其中酶催化有利于维尼洛基的1,4-合物添加.
- 形成了可调节玻璃过渡温度 (Tg) 从-18到80°C的寡合体.
- 仅生产低摩尔质量 (748-5949 g/mol) 的寡合物.
结论:
- 像酸这样的机体催化剂为不和乳的阳离子寡合化提供了一个高度有效的途径.
- 基和反应条件的选择允许对聚合机制进行选择性控制 (乙烯基类1,4-合物添加与环开放).
- 这种控制可以调整产生的寡合体的热性质和微观结构.
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