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通过分子动力学模拟,探索阿拉米德和PBO晶体的机械特性和故障机制

Hong-Li Yang^1,2, Ming Zhou^1,2, Bing Li¹

¹State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.

The Journal of chemical physics

|December 8, 2023

概括

这项研究模拟了高性能聚合物晶体的故障应激,如聚乙二甲胺 (PPTA) 和聚乙二甲胺 (PBIA),在不同的条件下. 结果显示,故障压力与温度和应变率相关,键位对齐影响了故障.

科学领域:

材料科学材料科学材料科学
计算化学的计算化学
聚合物物理聚合物物理

背景情况:

像PPTA,PBIA和PBO这样的高性能聚合物表现出卓越的机械性能.
了解它们在应力下失效的机制对于先进的材料设计至关重要.
现有的模型可能无法完全捕捉温度和应变速率在聚合物晶体断裂上的复杂相互作用.

研究的目的:

研究PPTA,PBIA,PBIA-PPTA和PBO晶体的机械性能和故障过程.
开发基于温度和拉伸率的故障应力预测模型.
阐明这些材料中分子层次的裂变机制.

主要方法:

用分子动力学模拟来分析聚合物晶体的行为.
在一系列温度和应变率的范围内进行了模拟.
分析包括应力-应变曲线,债券失败概率和形状变化.

主要成果:

失败压力和应变显示了与温度的线性关系和与应变速率的对数关系.
制定了一种新型模型来描述不同条件下的故障压力.
结合失效概率与PPTA,PBIA和PBIA-PPTA中的应变率和温度相关.
具有较大的初始对齐角度的键件更容易发生故障.
聚烯比索 (PBO) 呈现出影响其应力-应变行为的形状变化.

结论:

开发的模型准确地描述了研究的聚合物晶体的故障应力.
分子动力学模拟为聚合物裂变机制提供了宝贵的见解.
材料特性和故障模式受到温度,延展率和分子构造的显著影响.

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