多壁碳纳米管/聚乙烯醇复合材料电磁屏蔽性能研究

通过熔融共混、流延成膜法制备了多壁碳纳米管/聚乙烯醇(MWCNTs/PVA)复合材料,并研究了碳纤维作为增强体的作用。扫描电子显微镜、傅里叶变换红外光谱、热重分析表明:MWCNTs在PVA基体中均匀分散且形成了良好的空间导电网络;MWCNTs的加入会使吸收峰转移并与PVA发生键合反应;MWCNTs/PVA复合材料具有优异的热稳定性,热分解温度低于105℃时只有少量水分蒸发。导电性和电磁屏蔽测试表明,MWCNTs/PVA复合材料电磁屏蔽性能随其导电性的增强而提高,MWCNTs质量分数为1.2%的复合材料样品,在干扰电磁波频率为1~18GHz频段上具有良好的屏蔽性能,当干扰电磁波频率为13.3GHz时,其屏蔽效能为36.7dB。碳纤维可以增强MWCNTs/PVA复合材料的屏蔽性能,MWCNTs质量分数为0.6%的碳纤维增强MWCNTs/PVA复合材料样品,在干扰电磁波频率为1~18GHz频段时,其电磁屏蔽效能大于40dB。

Study on electromagnetic shielding performance of MWCNTs/PVA composite

Multiwalled carbon nanotubes/polyvinyl alcohol(MWCNTs/PVA)composite films were prepared by melt blending and casting film forming method,and the effect of carbon fiber as reinforcements was studied.SEM showed that MWCNTs was uniformly dispersed in the PVA matrix and formed a good spatial conductive network.FTIR analysis showed that the addition of MWCNTs would make the absorption peak transfer and the bonding reaction with PVA took place.Excellent thermal stability had only a small amount of water evaporation when below 105℃.Electrical conductivity and electromagnetic shielding tests shown that the electromagnetic shielding performance of MWCNTs/PVA-1.2 wt% samples was improved with the increase of electrical conductivity.The shielding peak value of MWCNTs/PVA-1.2 wt% samples was 36.7 dB,when the interference frequency was 13.3 GHz.At the same time,carbon fiber can enhance the shielding performance of MWCNTs/PVA film.The electromagnetic shielding efficiency of CF-MWCNTs/PVA-0.6 wt% sample was greater than 40 dB in 1~18 GHz band.