低填料比石墨烯/环氧树脂复合材料非线性电导机理的实验研究  

Experimental Study on Nonlinear Conduction Mechanism of Epoxy-based Nanocomposite with Low Content of Graphene Filler

作　　者：李禾[1] 王闯[1] 刘丽岚 张宇轩[1] 刘鹏[1] 彭宗仁[1] LI He, WANG Chuang, LIU Lilan, ZHANG Yuxuan, LIU Peng, PENG Zongren(State Key Laboratory of Electrical Insulation and Power Equipment, Xi＇an Jiaotong University, Xi＇an 710049, Chin)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室

出　　处：《高电压技术》2018年第3期812-820,共9页High Voltage Engineering

基　　金：国家自然科学基金(51521065);国家高技术研究发展计划(863计划)(2014AA051801)~~

摘　　要：为研究石墨烯导电填料的加入对环氧材料电导机理的影响,制备了不同填料质量比下石墨烯/环氧树脂复合材料。通过测量得到该复合体系的渗流阈值为质量分数1.35%,选择了石墨烯填料质量分数为0.3%、远低于渗流阈值的复合材料进行研究。利用高温高场强电导电流测试系统,测量了纯环氧材料和石墨烯/环氧复合材料在50、80和100℃下和0.24~14.4 k V/mm场强下的极化电流曲线。研究结果表明：直流电压作用下,两种材料的极化电流衰减速率均随场强和温度的增加而增大。随着场强的增大,两种材料的电导机理均发生了从欧姆电导到空间电荷限制电流理论（SCLC）为主导的转变,且这种转变电导电流场强阈值（Ethi）随温度的升高而降低。石墨烯填料的加入使环氧材料电导电流密度活化能增大,且活化能随着场强的增加逐渐降低,石墨烯/环氧复合材料在高场强区的电导机理受SCLC和隧道效应共同影响。In order to study the effects of conductive graphene fillers on the conductive mechanisms of epoxy-based materials, graphene/epoxy nanocomposites with different filler content were fabricated, and the conductive percolation threshold（1.35%） of graphene/epoxy systems were measured. Moreover, a DC conduction current measurement system was used for measuring the polarization current of neat epoxy and graphene/epoxy composites（0.3% of graphene filler） at different temperature（50, 80 and 100 ℃） and under the electric field of 0.24~14.4 k V/mm. The results indicate that the decay rate of polarization current of both composites increases with the increase of temperature and electric field. The main conduction mechanism of both composites transforms from ohmic conduction to space charge limited current（SCLC） conduction at a threshold of conduction current electric field（Ethi）, and the Ethi decreases with the increase of temperature. Moreover, the activation energy of conduction current density increases with the addition of graphene fillers, and the activation energy decreases with the increase of electric field. The conduction mechanisms of graphene/epoxy composites under high electric fields are influenced by SCLC and tunneling effect.

关 键 词：环氧树脂 石墨烯 纳米复合材料 非线性电导 电流密度 

分 类 号：TM21[一般工业技术—材料科学与工程]