Dielectric thermally conductive boron nitride/silica@MWCNTs/polyvinylidene fluoride composites via a combined electrospinning and hot press method
Zijian Wu, Shunying Gao, Xuefei Wang, Mohamed M. Ibrahim, Gaber A. M. Mersal, Juanna Ren, Zeinhom M. El‐Bahy, Ning Guo, Junguo Gao, Ling Weng, Zhanhu Guo
Abstract
Abstract With the development of microelectronics towards integration, miniaturization and high power, the accumulation of heat in this small space has become a serious problem. Therefore, polymer matrix composites with high thermal conductivity and electrical insulation need to be developed urgently. Here, an ordered oriented boron nitride/silicon dioxide (silica) coated multiwalled carbon nanotubes (BN/SiO 2 @MWCNTs) thermally conductive network was constructed in a polyvinylidene fluoride (PVDF) matrix by electrostatic spinning technique, and subsequently the PVDF composites were prepared by hot-pressing. The synergistic effect of two-dimensional BN and one-dimensional MWCNTs in PVDF was investigated. It was found that the out-of-plane thermal conductivity of BN 30 /SiO 2 @MWCNTs composites reached 0.4693 Wm −1 K −1 , which was 209% higher than that of pure PVDF and 10% higher than that of BN/PVDF composites. The in-plane thermal conductivity of BN 30 /SiO 2 @MWCNts) composites reached 1.5642 Wm −1 K −1 , which was 1055% higher than pure PVDF and 40% higher than BN/PVDF composites. This is attributed to the synergistic effect of BN on SiO 2 @MWCNTs. Meanwhile, the volume resistivity and breakdown strength of the BN/SiO 2 @MWCNTs/PVDF composites reached 3.6 × 10 13 Ω m and 47.68 kV/mm, respectively. The results indicate that the BN 30 /SiO 2 @MWCNTs/PVDF composites have excellent thermal conductivity and electrical insulating properties, which are promising for microelectronics applications.