EP/GNs/MWCNTs复合材料的导热性能

以多壁碳纳米管(MWCNTs)和石墨烯纳米微片(GNs)为导热填料,环氧树脂(EP)为基体采用溶剂和超声分散法,制备了EP/GNs/MWCNTs导热复合材料,并与EP/MWCNTs及EP/GNs复合材料的导热性能进行了对比。采用透射电子显微镜观察其微观结构,采用Hot Disk热导率测试仪测试其导热性能,采用差示扫描量热法和热重分析仪测试其耐热性及热稳定性。结果表明,MWCNTs和GNs共同作为EP导热填料时,相比于单组分填料(MWCNTs或GNs)更易形成导热网络;EP的热导率、玻璃化转变温度(Tg)和热分解温度均随着MWCNTs或GNs含量的增加而提高,其中,GNs更有利于提高EP的热导率和热分解温度,MWCNTs更有利于提高EP的Tg。在相同的导热填料含量下,相对于其中的任一单一填料,MWCNTs/GNs共同作用时,对热导率的提高有更显著的效果,且随着其中GNs比例的增加,热导率逐渐增大。当GNs和MWCNTs的体积分数分别为0.6%和0.4%时,EP/GNs/MWCNTs复合材料的热导率、Tg和起始分解温度分别为0.565 W/(m·K),152℃和316℃,分别比纯EP提高了132.5%,34.5%和8.2%。

Thermal Conductivity of EP/GNs/MWCNTs Composites

Multi-walled carbon nanotubes (MWCNTs) and graphene nanosheets (GNs) were used as thermal conductivefiller, epoxy resin (EP) was used as matrix,the EP/GNs/MWCNTs composites were prepared by solvent and ultrasonic dispersion method,the thermal conductive property of which was comparedto EP/MWCNTs and EP/GNs composites. Transmission electron microscope were used to analyze the microstructure of the composites. Hot Disk thermal conductivity meter was used to measure the thermal conductivity of the composites. Differential scanning calorimetry and thermal gravimetric analyzer were used to analyze the heat resistance and thermal stability of the composites. The experimental results demonstrate that it’s easier to form thermal conductive network in composites using the mixedfillers MWCNTs and GNs than using one single kind. The thermal conductiv-ity,glass transition temperature (Tg) and thermal decomposition temperature of EP increase gradually as the content of MWCNTs or GNs increases. Among these,GNs is more beneficial to improve the thermal conductivity and thermal decomposition temperature, MWCNTs is more beneficial to improveTg. Under the same contents of thefillers,the composites with mixedfiller does better than the one with single kind offiller in improving heat-conductivity properties,and the thermal conductivity of the composites increase as the content of GNs in the mixing GNs/MWCNTsfillers increases. When the volume fraction of GNs and MWCNTs is 0.6% and 0.4% respectively,the thermal conductivity,Tg and initial thermal decomposition temperature of EP/GNs/MWCNTs composite is 0.565 W/(m·K),152℃ and 316℃ separately,which improves by 132.5%,34.5% and 8.2% compared with pure EP.