在低压力循环负荷下聚合物纳米复合物的疲劳行为:从分子动力学模拟的见解
Tongkui Yue1, Hengheng Zhao1, Jiajun Qu1
1State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Langmuir : the ACS journal of surfaces and colloids
|November 4, 2024
概括
这项研究揭示了纳米颗粒度如何影响聚合物纳米复合材料疲劳. 较高度会增加纳米粒子聚合,将故障从聚合物转移到填充网,并提高疲劳抵抗力,直到临界点.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
- 计算材料科学科学 计算材料科学
背景情况:
- 耐疲劳性对于聚合物纳米复合材料 (PNC) 来说至关重要.
- 了解分子层面的结构演变和循环负荷下的键断裂是关键.
研究的目的:
- 为了研究纳米粒子填充分数对PNC疲劳行为的影响.
- 阐明循环变形下键断裂和故障的机制.
主要方法:
- 用不同碳黑纳米粒子分数对PNC进行分子动力学模拟.
- 循环拉伸变形疲劳测试与实时破解跟踪.
- 使用KWW方程和温度场观测对债券数自相关函数的分析.
主要成果:
- 增加的纳米粒子分数导致NP聚合和受限制的聚合物矩阵放松.
- 断键转移从聚合物到填充物网络的主导地位,分数越来越大,表明最大疲劳寿命的关键分数.
- 局部温度升高是主要的低应变失效机制,在循环中增加了聚合物和NP的移动性.
- 聚合物链的刚性影响疲劳寿命,显示与曲能量的非单调关系.
结论:
- 这项研究为PNC中疲劳机制提供了分子层面的理解.
- 这些发现指导了改进的耐疲劳聚合物纳米复合材料的设计.
- 建立了一个描述周期变形下故障行为的一般范式.
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