Simultaneously Enhanced Thermal Conductivity and Breakdown Performance of Micro/Nano-BN Co-Doped Epoxy Composites

Abstract

Micro/nano- BN co-doped epoxy composites were prepared and their thermal conductivity, breakdown strength at power frequency and voltage endurance time under high frequency bipolar square wave voltage were investigated. The thermal conductivity and breakdown performance were enhanced simultaneously in the composite with a loading concentration of 20 wt% BN at a micro/nano proportion of 95/5. The breakdown strength of 132 kV/mm at power frequency, the thermal conductivity of 0.81 W∙m−1∙K−1 and voltage endurance time of 166 s were obtained in the composites, which were approximately 28%, 286% and 349% higher than that of pristine epoxy resin. It is proposed that thermal conductive pathways are mainly constructed by micro-BN, leading to improved thermal conductivity and voltage endurance time. A model was introduced to illustrate the enhancement of the breakdown strength. The epoxy composites with high thermal conductivity and excellent breakdown performance could be feasible for insulating materials in high-frequency devices.

Research on the Compound Optimization Method of the Electrical and Thermal Properties of SiC/EP Composite Insulating Material

“…With the increase of the doping amount of nanoparticles, the thermal conductivity of the composite material decreased. Some previous studies also showed similar results: in the micro-nano composite system, the contribution of nanoparticles to the thermal conductivity is not as good as that of micro-particles [ 12 , 39 ]. This was because nanoparticles were too small in size compared to micro particles.…”

“…When the SiC filling amount increased, due to the micro-particles and the matrix interface were not tightly bonded, the internal air gap defects greatly increased, the development path of the electrical tree in the epoxy was shortened, and the breakdown strength was significantly reduced [ 36 , 37 ]. When other inorganic fillers such as SiO 2 and BN are used [ 38 , 39 ], the breakdown field strength of the composite material exhibits consistent characteristics at high filling ratios, and this trend is not conducive to the application of thermally conductive insulating materials.…”

A mucus-inspired solvent-free carbon dot-based nanofluid triggers significant tribological synergy for sulfonated h-BN reinforced epoxy composites

“…Fig. 5b shows that the h-BN@PSDA/EPs prepared in this work performs at an average level compared to other h-BN/EP composites, 45–51 which means that h-BN@PSDA nano-sheets are promising nano-fillers for improving the thermal and tribological properties of EPs.…”

Synergistic Enhanced Thermal Conductivity and Dielectric Constant of Epoxy Composites with Mesoporous Silica Coated Carbon Nanotube and Boron Nitride Nanosheet

“…Polymer dielectrics are extensively utilized in electronic devices because of their easy processing, flexibility, and light weight [ 1 , 2 , 3 , 4 , 5 , 6 ]. However, the low thermal conductivity of polymer dielectrics cannot meet the rising demand of efficient heat dissipation due to continues miniaturization electronic devices with high speed and high power [ 5 , 7 , 8 , 9 ]. Incorporation of thermally conductive fillers into polymer matrix is regarding as an effective strategy to improve the thermal conductivity of materials [ 10 , 11 , 12 , 13 , 14 ].…”