低界面热阻改性氮化铝和多壁碳纳米管充填PVDF构建杂化三维网络及其导热性能强化

通过对多壁碳纳米管(MWCNT)和氮化铝(AlN)颗粒进行不同的改性，提高其分散性以及与聚偏氟乙烯(PVDF)基体的界面相容性，降低界面热阻。通过溶液共混后再用热压法将填料与基体的混合物压制成致密的薄膜，提高PVDF的导热性能。TEM测试证明改性后的填料分散性能提高，SEM证明两种填料成功地在PVDF基体中构成三维杂化网络结构。当填料含量50%时，a-AlN-PVDF复合薄膜的热导率达到原膜的300%、断裂强度变为原膜的92%。当MWCNT与AlN的体积比为1∶1、改性混合填料的质量分数为50%时，热导率变为原膜的565%，断裂强度变为原来的51%。

Construction of three-dimensional network by modified MWCNT and AlN fillings in PVDF to improve the thermal conductivity

Based on multi-walled carbon nanotube (MWCNT) and aluminum nitride (AlN) particles with different modification, to improve the dispersion and interfacial compatibility with PVDF matrix, and reduce the interfacial thermal resistance. After solution blending, the mixture of filler and matrix is pressed into a dense film by hot pressing to improve the thermal conductivity of PVDF. By this method a three-dimensional hybrid network structure was expected to be constructed. TEM tests showed that the dispersion property of the modified fillers was improved, and SEM showed that the two fillers successfully formed a three-dimensional hybrid network structure in PVDF matrix. When the filler content is 50%, the thermal conductivity of the a-AlN-PVDF composite film reaches 300% of the original film, and the breaking strength becomes 92% of the original film. When the volume ratio of MWCNT to AlN is 1∶1 and the mass fraction of the modified mixed filler is 50%, the thermal conductivity becomes 565% of the original film and the breaking strength becomes 51% of the original film.