具有高密度可逆键的关联聚合物的动力学
Shifeng Nian1, Shalin Patil2, Siteng Zhang3
1Soft Biomatter Laboratory, Department of Materials Science and Engineering, University of Virginia, Charlottesville, Virginia 22904, USA.
Physical review letters
|June 16, 2023
概括
具有许多贴纸的关联聚合物显示动态放缓但不变的粘弹性光谱,挑战现有理论. 这表明可逆键意外地影响了聚合物结构放松.
科学领域:
- 聚合物科学 聚合物科学
- 材料科学是一种材料科学.
- 物理化学 物理化学
背景情况:
- 结合性聚合物具有形成可逆键的贴纸,传统上被认为通过作为临时交叉链接,在粘弹性光谱中创建一个状高原.
- 这种既定的理解表明,由于这些可逆的关联,线性粘弹性光谱的形状发生了显著的变化.
研究的目的:
- 设计和合成具有异常高的贴纸分数 (每Kuhn段高达八个) 的新型关联聚合物.
- 研究强对键 (∼20k_{B}T) 对聚合物动力学和粘弹性质的影响,而无需诱导微相分离.
主要方法:
- 合成高贴纸密度的新类非纠联聚合物.
- 线性粘弹性光谱和聚合物动态的实验性表征.
- 使用重新规范化的Rouse模型进行理论分析.
主要成果:
- 合成的聚合物由于可逆结合而表现出显著减缓的动态.
- 与预期相反,线性粘弹性光谱显示出形状的最小变化.
- 实验数据与重新规范化的Rouse模型保持一致,表明可逆键在结构放松中的意想不到的作用.
结论:
- 具有强键的高贴纸密度关联聚合物不会像之前预测的那样改变粘弹性光谱的形状.
- 可逆键对聚合物动力学和结构放松有深远的影响,需要修订理论框架.
- 这些发现挑战了长期以来的观点,即可逆的关联仅仅作为影响光谱形状的交叉链接.
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