Dielectric Properties and Thermal Conductivity of Polyvinylidene Fluoride Synergistically Enhanced with Silica@Multi-walled Carbon Nanotubes and Boron Nitride

There is an urgent need for polymer composites with high thermal conductivity and electrical insulation in microelectronic packaging. Due to their fascinating chemical and physical properties, multi-walled carbon nanotubes (MWCNTs) have enabled major achievements in polymer composites fields as a reinforcement filler. Nevertheless, high conductivity of raw MWCNTs (R-MWCNTs) was an obstacle to wider application of the CNTs in some special fields, which require outstanding thermal conductivity and insulation properties simultaneously. In this work, silica@MWCNTs were prepared to reduce the electrical conductivity. The composites were prepared by doping BN and silica@MWCNTs through hot press method. The results showed that the thermal conductivity of BN-SiO2@MWCNT/PVDF was higher than that of BN/PVDF and pure PVDF. When the content of BN was 30wt%, the thermal conductivity of BN-SiO2@MWCNT/PVDF increased to 0.4084 W/(m·K), which was 170% higher than that of pure PVDF. The dielectric constant, dielectric loss and conductivity of PVDF increased when only MWCNT was added, while the dielectric constant, dielectric loss and conductivity of the composite decreased with the increase of BN content after adding BN.