基于尿素的双功能器官催化剂促进了racemic乳化物的动态分辨率聚合,使其变异性多聚乳化
Jiang Dai1, Wei Xiong1, Dong-Yu Li1
1National Engineering Laboratory of Eco-Friendly Polymeric Materials (Sichuan), College of Chemistry, Sichuan University, Chengdu 610064, People's Republic of China. zzcai@scu.edu.cn.
概括
基于尿素的新型有机催化剂使乳酸 (LA) 的立体选择性聚合能够产生高同位丰富的多乳酸 (PLA). 这种增强的PLA表现出更好的热性能,形成具有更高点的立体复合体.
科学领域:
- 有机化学 有机化学
- 聚合物科学 聚合物科学
- 催化剂是一种催化剂.
背景情况:
- 基于尿素的有机催化剂越来越多地用于不对称合成.
- 乳酸等周期性的立体选择性聚合对于生产先进的聚合物材料至关重要.
- 控制聚合物战术性会影响材料特性,例如热稳定性.
研究的目的:
- 为了合成和评估基于硫尿素的新型有机催化剂,用于种族乳酸 (rac-LA) 的立体选择性聚合.
- 研究催化剂立体化学对产生的多乳酸 (PLA) 战术性的影响.
- 探索立体复杂PLA的形成及其对热性质的影响.
主要方法:
- 一系列基于尿素的有机催化剂 (1-7) 的合成,其中包括双纳胺和环二胺部分.
- 使用催化剂 (R,S) -1 和其反聚合物 (S,R) -1 的rac-LA的立体选择环开放聚合.
- 聚合物战术性 (P_m) 和差异扫描热量计 (DSC) 的分析,以确定生成的PLA和立体复合物的化温度 (T_m).
主要成果:
- 催化剂 (R,S) - 1成功地产生了以P_m为0.96.9的异位丰富的聚D乳酸 (PDLA).
- 酵素酶催化剂 (S,R) - 1产生了以 0.96.m 的 P_m 的异构丰富的聚L-乳酸 (PLLA).
- 以异位丰富的PLA样本形成了立体复合体,导致化温度 (T_m) 显著增加,达到196°C.
结论:
- 开发的基于硫尿素的有机催化剂有效地控制了LA聚合中的立体选择性.
- 可以实现PLA的高同位丰富,从而提高材料性能.
- 立体复合体形成显著提高了PLA的热稳定性,由T_m的升高证明了这一点.
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