以炭黑(CB3100)为导电相,硅橡胶为基质制备导电复合材料。研究导电橡胶中炭黑质量分数对电阻温度系数的影响,并用填料对电阻温度系数的影响。以隧道效应理论为基础,给出了导电炭黑填充橡胶的电阻温度系数计算模型,结合实验得到温度对导电炭黑/硅橡胶电阻温度系数的影响主要体现在对其电阻率的影响;基体的体积热膨胀提高复合材料的电阻率,提高了正电阻温度系数;炭黑粒子间的隧道效应降低复合材料的电阻率,增强了负电阻温度系数;在炭黑/硅橡胶中加入少量碳纳米管,利用碳纳米管和炭黑的协同补强效应,使复合材料的导电性和稳定性提高。
Conductive composites are consisting of carbon particles(CB3100) and silicone rubber matrix.The temperature coefficient of resistance(TCR) based on conductive silicon rubber was analyzed for the dosage of filler,and studied the different filler blend in the conductive composites.Analysis the resistivity calculation model of conductive carbon black/silicone rubber which based on the theory of tunneling,the TCR model has been calculated,combined with experiments: temperature effects the TCR of the conductive carbon black/silicone rubber,by act on resistivity of conductive carbon black/silicone rubber;the volume thermal expansion of matrix increased the resistivity of composites,the positive TCR of conductive composites enhanced;tunnel effect between carbon black particles reduces the resistivity of composite materials,the negative TCR of conductive composites enhanced.By adding a small amount of carbon nanotubes in the carbon black/silicone rubber,due to the synergetic effect of carbon nanotubes and carbon black in a rubber system,conductivity and stability of conductive composites enhanced.