炭黑对ASA/天然石墨复合材料的电磁屏蔽性能影响

Effects of Carbon Black on Electromagnetic Shielding Performance of ASA/NGR Composites

通过熔融共混方法制备导电高分子复合材料丙烯腈-苯乙烯-丙烯酸酯共聚物(ASA)/天然石墨(NGR)/炭黑(CB),采用电磁屏蔽测量仪、四探针电阻率测量仪和动态热机械分析仪对复合材料的电性能和力学性能进行详细研究。结果表明,ASA/NGR复合材料的体积电阻率随着炭黑含量增加而增加;同时在30 MHz~1500 MHz范围内,复合材料的电磁屏蔽性能从28 dB提高到38 dB,符合商业要求。炭黑的加入大大改善了材料力学性能,弯曲强度从31 MPa增加到41 MPa;动态储能模量从4.6 GPa增加到14.5 GPa。

Acrylonitrile-styrene-acrylate(ASA)/natural graphite(NGR)/carbon black(CB)composites were produced by the melting method and were analyzed by using electromagnetic shielding apparatus,four probe resistivity meter and dynamic thermomechanical analyzer(DMA).The results show that the volume electrical resistivity increases with the carbon black content increasing.And the electromagnetic interference shielding effectiveness(EMI SE)of ASA/NGR/CB composites increases from 28 dB to 38 dB in the range of 30~1500 MHz,which could meet the requirement of commerce.In addition,the addition of carbon black could largely improve the mechanical properties of ASA composites,flexural strength of composites could increase from 31 MPa to 41 MPa and the storage modulus of composites could increase from 4.6 GPa to 14.5 GPa.