Abstract:

Bulk polyethylene material is an insulator,whose thermal conductivity could be improved by doping or stretching methods etc,but a single polyethylene chain owns a considerably high thermal conductivity. For polyethylene chains,a detailed calculation is made on the thermal conductivity of original single chain,several chains,torsional chains and stretching chains using equilibrium molecular dynamics methods. Results show that,the thermal conductivity of a single torsional chain decreases slightly,but the thermal conductivity of several chains improves a little when the chains twisted in a particular way. Besides,the thermal conductivity of several chains could achieve a great improvement under stretching loading. Based on above results,a torsional and stretching strand accompanied by better heat-conducting properties is introduced. It has a great significance in guiding the improvement work of the heat conduction of polymer chains under a variety of physical loading.

Key words: polyethylene chain, thermal conductivity, molecular dynamics, torsional, heat conduction, model, numerical analysis

摘要：

聚乙烯块体材料是一种绝缘体，其导热性能可以通过掺杂或拉伸等方法提升，纳米尺度下的聚乙烯单链沿长度方向拥有很高的热导率。针对聚乙烯链，通过平衡态分子动力学方法对原始单链、多链、扭转链和拉伸链进行热导率计算。结果显示，单链扭转后其热导率小幅度降低，多链按照特定方式扭转会小幅度增强整体的热导率。此外，多链整体拉伸时热导率会极大地提升。基于上述结果提出一种导热性能更好的扭转拉伸链。研究结果可对多种物理过程作用下聚合物链导热性能的提升工作提供参考。

关键词: 聚乙烯链, 热导率, 分子动力学, 扭转, 热传导, 模型, 数值分析