单分散循环聚合物机械化学:超声波和球磨机的裂变动力学和动态记忆效应
Jinkyung Noh1, Mo Beom Koo1, Jisoo Jung1
1Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea.
Journal of the American Chemical Society
|July 24, 2023
概括
在超声波下,线性多聚酸比循环多聚酸具有显著更高的机械化学反应性,揭示了聚合物降解和循环结构效应的洞察力.
科学领域:
- 聚合物化学
- 材料科学
- 机械化学
背景情况:
- 了解聚合物降解机制对于材料设计和应用至关重要.
- 由机械力驱动的机械化学反应提供了聚合物修饰和降解的独特途径.
- 循环聚合物架构可以影响与线性对应物相比的反应性.
研究的目的:
- 调查单分散周期性和线性多酸 (c-PLA和l-PLA) 的机械化学反应性.
- 在超声波 (US) 和球磨机 (BMG) 下比较降解动力学.
- 阐明周期性聚合物结构对裂变速率和碎片化的影响.
主要方法:
- 单分散的循环和线性多分子 (d,l-lactide) 的合成,可控制的聚合度.
- 应用超声波 (US) 和球磨机 (BMG) 来诱导机械化学降解.
- 聚合物降解动力学和碎片分子重量分布的分析.
主要成果:
- 线性PLA的裂变率高达US周期性PLA的9.0倍,BMG的差异较小 (1.9倍).
- 对周期性PLA观察到单个骨干裂变的线性中间体,这表明有两次裂变的碎片化过程.
- 通过分析碎片分子重量分布,开发了一种用于研究美国动态记忆效应的新方法.
结论:
- 循环聚合物结构显著影响机械化学降解率,线性聚合物更容易受到影响,特别是在美国.
- 这项研究提供了循环PLA机械化学降解中的线性中间体的首次观察.
- 美国和BMG之间的反应性差异突显了机械化学过程中的机械环境的重要性.
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