单轴压力对高密度聚乙烯/碳黑导电复合材料电阻特性的影响

Effect of Uniaxial Pressures on the Resistance of High Density Polyethylene/Carbon Black Composites

研究了高密度聚乙烯 /炭黑导电复合材料在单轴压力作用下电阻的变化规律 .结果表明 ,在低压力下 ,复合材料电阻随压力增加而降低 ;而在较高压力下则随压力增大而升高 ,分别呈现出所谓的“电阻负压力系数”和“电阻正压力系数”效应 .电阻的压力依赖性以及由压缩引起的电阻不可回复性 ,被认为与外力作用下导电网络的重组与破坏有关 .由此提出了导电复合材料单轴压力作用

The relationship between uniaxial pressures and resistance of high density polyethylene/carbon black(HDPE/CB) composites was studied. The results showed that there existed a critical pressure below which composite resistance decreased with the increase of pressure and above which resistance increased with the increase of pressure. Correspondingly, these behaviors were defined as negative and positive pressure coefficient of resistance in this work. There existed obvious electrical hysteresis during unloading procedures. Nonrecoverable resistance was found when pressures approached to zero. It was believed that the uniaxial pressures resistance relations were involved in the reformation and destructure of conductive network under pressures. A simple piezoresistive model was proposed phenomenologically to explain the experimental results.