Enhancing mechanical property and thermal conductivity of fluororubber by the synergistic effect of CNT and BN

Fluororubber (FKM) shows great potential in the sealing field of high-end equipment components due to its excellent mechanical properties and sealing performance. However its low thermal conductivity limits its application in a wider range of fields. Here, we compounded hexagonal boron nitride (BN) nanosheets and single-walled carbon nanotubes (CNT), and then introduced them into FKM matrix to enhance its thermal conductivity and mechanical properties, thus x-BN/CNT/FKM composites (x represents filler addition amount) were prepared. The results show that the synergy between BN and CNT contributes to the formation of three-dimensional filler network, which improves its mechanical properties and promotes the formation of efficient three-dimensional heat conduction network. Compared with original FKM and x-BN/FKM composites, x-BN/CNT/FKM composites shows better vulcanization performance, enhanced mechanical properties, thermal conductivity and thermal stability. Especially, the thermal conductivity of 2BN/CNT/FKM composites reached 0.395 W/(m·k), which was 28.2 % higher than that of original FKM composites. In addition, the thermal management performance analysis also shows that 2BN/CNT/FKM composites possess excellent heat transfer ability during heating and cooling processes. 2BN/CNT/FKM composites have great application potential in the fields of high-end sealing materials, due to their remarkably improved mechanical performance and thermal conductivity at low filling level.