环氧树脂/CF/亚麻纤维复合材料电磁屏蔽性能

Electromagnetic Shielding Performance of Epoxy/CF Power/Flax Fiber Composites

电子电气设备等产生电磁辐射污染会严重影响到人体健康,并干扰设备的正常运行,解决电磁污染的关键是使用电磁屏蔽材料。采用模压工艺制备了具有电磁屏蔽功能的环氧树脂/碳纤维(CF)/亚麻纤维复合材料。借助矢量网络分析仪、热重分析仪、万能试验机、扫描电子显微镜(SEM)等研究CF粉对复合材料的电磁屏蔽性能(EMI SE)、热稳定性和力学性能的影响。结果表明,复合材料的弯曲强度随着CF粉含量的增加而增加,并在其质量分数为30%时达到最大值,为102.5 MPa,与未加CF的材料相比较,提高了31.1%,此后进一步增加CF粉含量,复合材料的弯曲强度开始下降。SEM证实,复合材料力学性能的提高来源于CF与环氧树脂界面性能的改善。CF粉的加入提高了环氧树脂/亚麻纤维复合材料的热稳定性,热分解温度从206℃提高到268℃。同时复合材料的体积电阻率随着CF粉含量的增加而下降,从0.65Ω·cm降至0.132Ω·cm。在8.4~12.4 GHz电磁波范围内,环氧树脂/CF/亚麻纤维复合材料的EMI SE达到20 dB以上,基本满足商业要求。

The electromagnetic shielding pollution caused by the rapid development of electronic and electrical equipment could seriously affected human health and interfered with the normal operation of equipment.The key to solving the pollution is to use electromagnetic shielding materials.Epoxy resin/carbon fiber(CF)/flax fiber composite materials were prepared using a molding method.The effects of CF powder on the electromagnetic shielding(EMI SE) performance,thermal stability,and mechanical properties of composites were studied using a vector network analyzer,thermogravimetric analyzers,universal testing machines,and scanning electron microscopy(SEM).The results indicate that the bending strength of the composite material increases with the increasing of CF powder content,and reaches the maximum value(102.5 MPa) at 30%,increasing by 31.1% as compared with nonCF composite.Afterwards,the bending strength gradually decreases.SEM confirmes that the improvement in material mechanical properties is attributed to the good interface performance between CF and epoxy resin.The addition of CF powder improves the thermal stability of composite material,the thermal decomposition temperature increases from 206 ℃ to 268 ℃.The volume resistivity of composite materials gradually decreases from 0.65 Ω·cm to 0.132 Ω·cm with the increase of CF powder content.The EMI SE of epoxy resin/CF powder/flax fiber composite material reaches over 20 dB in the range of 8.4-12.4 GHz,basically meets with commercial requirements.