在电场下的多重放松动态使得在玻璃过渡温度以上的聚甲酸可调节的粘弹性反应
Yinuo Teng1, Yunlong Guo1,2
1University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240, China.
The Journal of chemical physics
|January 23, 2024
概括
电场通过影响链运动来调整聚合物力学. 局部分段极化增强了刚性,而更大规模的变化促进了聚甲酸 (PMMA) 在其玻璃过渡温度 (Tg) 以上的更快放松和降低粘度.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学 材料科学 材料科学
- 类风病学 类风病学 类风病学
背景情况:
- 响应刺激的聚合物需要优化的机械性能来实现实际应用.
- 由于粘性弹性,理解聚合物在外部场下的行为是复杂的.
研究的目的:
- 在电刺激下研究聚甲酸 (PMMA) 的现场动态和静态机械反应,其玻璃过渡温度 (Tg) 以上.
- 阐明电机反应与聚合物链放松模式之间的相关性.
主要方法:
- 将直流电场垂直应用于Tg以上的PMMA样本的机械负荷.
- 分析动态和静态机械反应,包括模块,瞬态粘度,线性粘弹性范围和流动粘度.
主要成果:
- 局部分段极化通过抵抗分子运动来增强模块,瞬时粘度和线性粘弹性范围.
- 大规模的极化诱导的形状变化导致了更快的放松,减少了弹性模量和降低了模量平原.
- 由于在电极化下减少链间摩擦,流体粘度下降.
结论:
- 在Tg以上的PMMA的电机反应与各种长度尺度的链松动动态密切相关.
- 电刺激为高于Tg的聚合物粘弹性行为的精确调整提供了有效的策略.
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