多壁碳纳米管改性UHMWPE的热膨胀和摩擦学性能研究

Thermal Expansion and Tribological Properties of Multi-walled Carbon Nanotubes Modified UHMWPE

为了降低摩擦副用聚合物的热膨胀系数,用多壁碳纳米管(MWCNTs)改性超高分子量聚乙烯(UHMWPE),通过热压成型法制备MWCNTs/UHMWPE复合材料。通过测量电导率计算渗流阈值来表征分散性;用热膨胀仪(DIL)测试复合材料的热膨胀率,并在干摩擦环境下,测试不同MWCNTs含量复合材料的摩擦学性能。结果表明:通过无水乙醇超声分散再研磨的方法得到的复合材料具有较好的分散性;MWCNTs可以有效改善UHMWPE的热膨胀性能,且不会降低UHMWPE的摩擦学性能,其中质量分数0.8%MWCNTs改性的复合材料表现出优异的减摩抗磨性;热膨胀系数与摩擦学性能表现出一定的相关性,热膨胀系数越小,耐磨性越好。

In order to reduce the thermal expansion coefficient of the polymer used as friction pair, the ultra-high molecular weight polyethylene(UHMWPE) was modified with multi-walled carbon nanotubes(MWCNTs),and the MWCNTs/UHMWPE composite material was prepared by the hot pressing method.The percolation threshold was calculated by measuring the conductivity to characterize the dispersion.The thermal expansion rate of the composite was tested with a thermal dilatometer(DIL),and the tribological properties of the composites with different MWCNTs contents were tested in a dry friction environment.The results show that the composite material obtained by the method of alcohol ultrasonic dispersion and regrind has good dispersibility.MWCNTs can effectively improve the thermal expansion properties of UHMWPE without reducing the tribological properties of UHMWPE.The composite material modified by mass fraction of 0.8% MWCNTs shows excellent friction reducing and anti-wear properties.The thermal expansion coefficient shows a correlation with the tribological properties, the lower the thermal expansion coefficient, the better the wear resistance.