碳纳米管．聚乙烯复合材料界面力学特性分析

摘要

本文采用分子动力学模拟办法对碳纳米管．聚乙烯复合材料的界面力学特性进行了模拟和分析．通过对单壁碳纳米管从无定形聚乙烯中抽出过程进行模拟，研究了界面剪切应力随碳管滑移速度、聚乙烯分子链长和碳纳米管管径之间的变化关系，并对界面的滑移机理进行了讨论．模拟结果发现，随着聚合物分子链长的增加，界面临界剪切应力有显著增大，而滑移剪切应力略显增加；界面临界剪切应力和滑移剪切应力随着碳纳米管管径的增大而明显增加．本文同时对界面应力的变化机理进行了模拟和讨论．%In this paper, the interfacial mechanical properties of carbon nanotube-polyethylene （CNT-PE） composite are investigated by using classical molecular dynamics simulation. Basd on the simulations for the CNT pulling-out process from the PE, the influences of the CNT sliding velocity, the chain length of PE and the radius of CNT on the interfacial shear stress are explored. As the chain length of PE increases, the critical interfacial shear stress increases remarkably while the sliding shear stress increases slightly. Both the critical shear stress and the sliding shear stress increase with the radius of CNT enlarging. Moreover, the mechanism for the variation of interfacial shear stress is analyzed and discussed.