在PEG甲基酸盐的光化器RAFT聚合过程中溶剂和温度的影响
Roujia Chang1, Bryn D Monnery1, Inge S Zuhorn1
1Department of Biomaterials & Biomedical Technology, University Medical Center Groningen, University of Groningen Antonius Deusinglaan 1 9713 AV Groningen The Netherlands bryn.monnery@gmail.com i.zuhorn@umcg.nl.
Polymer chemistry
|June 2, 2025
概括
光化剂 (PI) -RAFT聚合使得像P(PEGMA等聚合物的受控合成成为可能. 溶剂选择显著影响聚合动力学,而异离子被证明是保持低分散率的最佳选择,即使在高温下也是如此.
科学领域:
- 聚合物化学 聚合物化学
- 材料科学 材料科学 材料科学
背景情况:
- 光化 (PI) -RAFT聚合提供了一个高度"活"的方法来合成 (甲基) 和烯聚合物,最大限度地减少终结.
- 聚乙烯基醇甲基乙甲基酸盐 (PEGMA) 是一个有前途的生物相容性材料,但由于反应性自由基,其聚合控制具有挑战性.
研究的目的:
- 通过PI-RAFT聚合,研究P(PEGMA) 的合成.
- 探索包括溶剂在内的各种反应条件对PI-RAFT聚合动力学和机制的影响.
- 确定溶剂对传播速率和控制P (PEGMA) 合成的影响.
主要方法:
- 通过PI-RAFT聚合在各种条件下合成P(PEGMA):激发波长,单体度,温度和溶剂.
- 计算的传播常数 (kp),阿雷尼乌斯参数,力 (ΔH‡) 和激活力 (ΔS‡).
- 进行了回归分析,将动态数据与链传递剂 (CTA) 的灭绝系数和溶剂特性相关联.
主要成果:
- 传播常数 (kp) 受到RAFT平衡的影响;对于不同的溶剂,确定了Arrhenius参数.
- 有效碰撞因子 (A) 与CTA灭绝系数有很强的相关性,表明激发依赖.
- 溶剂极性尺度 (KAT,加泰罗尼亚语) 无法准确预测动力参数; 醇成为最佳溶剂,在40°C时产生1.30的分散度 (Đ).
结论:
- PI-RAFT聚合能对P(PEGMA) 合成提供良好的控制,由链转移常量 (Ctr) > 1证明.
- 温度会影响Ctr,而较高的温度会由于Kp增加而降低Ctr.
- 溶剂的选择对于PI-RAFT聚合动力学和控制至关重要,无离子体表现出卓越的性能.
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