二氧化硅对EP/CB复合材料电性能的影响

Influences of Silica on Electrical Properties of EP/CB Composites

以二氧化硅(SiO2)为添加剂,低结构炭黑(CB)为导电填料,环氧树脂(EP)为基体树脂,甲基四氢邻苯二甲酸酐(MeTHPA)为固化剂,采用超声分散溶液混合法制备EP/CB/SiO2复合材料。通过电阻–温度特性测试和扫描电镜等分别对其电性能和微观形貌进行了表征与分析。结果表明,随SiO2含量增加,复合材料的室温体积电阻率先下降后上升,当SiO2质量分数为0.5%时,电阻率达到最小值;含SiO2的EP/CB/SiO2导电复合材料仍具有正温度系数(PTC)和负温度系数(NTC)效应,但其PTC强度小于EP/CB复合材料,NTC效应也弱于EP/CB体系。

With SiO2 as additional agent, low structure carbon black （ CB ） as conductive filler, epoxy resin （ EP ） as matrix resin, MeTHPA as curing agent, the EP / CB / SiO2 composites were prepared by ultrasonic dispersion and solution blending. Its electric properties and morphology were characterized and analyzed by resistance-temperature characteristic test and scanning electron microscopy （ SEM ） .The results showed that the volume resistivity of composites under room temperature decreased with an increase in silica contents and showed a minimum with silica content of 0.5wt%.Resistivity then increased with the addition of excess amount of silica.The EP / CB / SiO2 conductive composites still had PTC（ positive temperature coefficient ）and NTC（ negative temperature coefficient ） efficiency, but its PTC and NTC intensity was less than that of EP / CB composites.