负温下炭黑/树脂复合材料温度敏感特性

Temperature-sensitive characteristics of carbon/epoxy composites under negative temperature

对纳米炭黑填充的树脂基导电复合材料负温下的温度响应进行了试验研究。试验发现,该导电复合材料在负温下具有正温度系数(PTC)特性,电阻值随温度的降低而降低,随温度的升高而升高。炭黑含量对其温度敏感性的影响是明显的,35%配方的温度灵敏度最好,随着炭黑含量增大,灵敏度逐渐降低。分析认为,树脂基材料的热胀冷缩是导致该复合材料热敏性的主要原因;炭黑含量越高,材料内部的导电网络越稳定,温度变化对电阻的影响越小。

The temperature response of carbon/epoxy composites under negative temperature was studied. It is found that the conductive composite material have a positive temperature coefficient（ PTC） properties under negative temperature,the resistance value decreases with decreasing temperature and increases with increasing temperature. Effect of carbon black on the temperature sensitivity is obvious. Sample with35% carbon black content has best temperature sensitivity. As the carbon black content increases,sensitivity decreases. Thermal expansion and contraction of the resin-based material is the main reason leading to the composite heat-sensitivity. The conductive network inside the material would be more stable when the carbon black content become higher and hence the effect of temperature on resistance was smaller.