负责流动诱导的聚合物机械化学的分子条件的实验量化
Robert T O'Neill1, Roman Boulatov2
1Department of Chemistry, University of Liverpool, Liverpool, UK.
Nature chemistry
|July 10, 2023
概括
了解快速流动中的聚合物链断裂是关键. 新的方法显示,在断裂过程中,只有聚合物链的一小部分被过度拉伸,力量集中在离中心远的地方.
科学领域:
- 聚合物科学 聚合物科学
- 机械化学 机械化学
- 物理化学 物理化学
背景情况:
- 快速流动中的宏分子碎片化对于基本和实际应用至关重要.
- 由于可视化限制,导致聚合物链断裂的精确分子事件尚未得到充分理解.
研究的目的:
- 研究在超声波溶液中经历机械化学反应的聚合物链的分子动力学和几何学.
- 描述聚合物链断裂过程中的分子几何分布.
主要方法:
- 利用聚乙烯链断裂和染色体异构化之间的同链竞争分析.
- 研究了在超声波溶液中的机械化学反应,以推断分子事件.
主要成果:
- 确定在碎片化过程中不到30%的聚合物骨干过度拉伸.
- 发现最大的力和反应概率位于距离链的中心.
- 观察到过度伸展的段落与机械化学反应同时在脊柱上生长和漂移.
结论:
- 量化链内竞争提供了对快速流动中的聚合物链断裂的机制性见解.
- 这些发现挑战了关于破裂聚合物链中均应力分布的假设.
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