用盐更好:在中性pH的水性环开放转化聚合
Jeffrey C Foster1, Marcus C Grocott1, Lucy A Arkinstall1
1School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom.
Journal of the American Chemical Society
|July 17, 2020
概括
水性环开转化聚合 (ROMP) 对离子敏感,可使催化剂失效. 添加盐可以增强单体的转化和控制,使得二块共聚物在水中合成.
科学领域:
- 聚合物化学
- 绿色化学
- 材料科学
背景情况:
- 水性环开转化聚合 (ROMP) 提供环保的聚合物合成.
- 已知水溶性催化剂具有交叉转移 (CM) 和环闭转移 (RCM),但它们的水性ROMP性能不太清楚.
- 了解水性ROMP中的催化剂行为对于生物大分子功能化和纳米粒子制备等应用至关重要.
研究的目的:
- 研究pH,盐添加剂和催化剂负荷对水性ROMP的影响.
- 在水性ROMP中确定催化剂失活的原因.
- 优化水性ROMP和共聚合物合成的条件.
主要方法:
- 在不同的pH值,化物度和催化剂负载下研究水性ROMP.
- 分析了催化剂失活机制,提出了Ru- ((OH) 复合物的形成.
- 使用ROMP诱导自组合 (ROMPISA) 与不同源合成的双块共聚物.
主要成果:
- 水性ROMP对化物度敏感,低度导致单体转化和催化剂寿命缩短.
- 在中心的氧化物或水的取代导致了催化剂的失活.
- 添加化物盐 (NaCl,KCl,四甲) 显著改善了ROMP转化和控制.
- 通过ROMPISA在90%的水中用1mol%的催化剂成功合成了迪布洛克共聚物.
结论:
- 离子对于稳定水性ROMP中的催化剂至关重要.
- 优化的水性ROMP条件可以有效合成聚合物和共聚合物.
- 中性pH的水性ROMP为生物介质的应用提供了新的可能性.
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