碳酸钙对炭黑/环氧树脂复合材料电性能的影响

Influence of CaCO_3 on Electrical Properties of Carbon Black / Epoxy Composites

研究了CaCO3对CB/EP体系室温体积电阻率及阻温特性的影响。以碳酸钙(CaCO3)为改性剂,炭黑(CB)为导电填料,环氧树脂(EP)为基体树脂,2-乙基-4-甲基咪唑(2,4-EMI),采用超声分散法制备了CaCO3/CB/EP复合材料。通过对其室温体积电阻率和电阻-温度特性的测试,结合扫描电镜等进行了微观形貌表征与分析。结果表明,在CB含量为14%的CaCO3/CB/EP体系中,随CaCO3含量增加,复合材料的室温体积电阻率先下降后上升,在0.5∶1(CaCO3∶CB)时达到最小值;含CaCO3的EP/CB导电复合材料PTC(正温度系数)效应强于CB/EP复合材料,在测试温度范围内没有出现NTC(负温度系数)效应。

This paper studies the influnce of CaCO3 content on the room volume resistivity and resistance-temperature characteristics of CB/EP composite.With CaCO3 as additional agent,carbon black （CB）as conductive filler,epoxy resin （EP）as matrix resin,2-ethyl-4-methyl-imidazo（2,4-EMI）as curing agent,the CO3/CB/EP composites were prepared by ultrasonic dispersion.Its room volume temperature resistance and volume resistance-temperature characteristics were tested,morphology properties were analyzed by scanning electron microscopy.The results show that,in the system of CaCO3/CB/EP which CB content is 14％,with increase of CaCO3content,the room volume temperature volume resistivity of the composites decreases and then increases.The volume resistivity reaches minimum at a ration of 0.5∶1 （CaCO3∶ CB）.The PTC （Positive temperature coefficient）effect of the CaCO3/CB/EP composite material is stronger than that of EP/CB composite material,and it has no NTC （Negative temperature coefficient）effect within the test temperature.