Improving the thermal conductivity of PMIA/EP composites by the synergistic effect of modified boron nitride and graphene oxide

In this study, h-BN-OH was obtained by hydroxylating h-BN and subsequently KH560 was grafted onto the surface of h-BN-OH, resulting in h-BN-KH560. The h-BN-KH560 was then dispersed in an epoxy resin (EP) to create an EP/h-BN-KH560 adhesive solution, with the content of h-BN-KH560 being varied. Graphene oxide (GO) was dispersed in PMIA precipitated fibers to produce PMIA/GO composite paper. Finally, the surface of the composite paper was evenly coated with the EP/h-BN-KH560 adhesive solution, and then PMIA/EP/GO/h-BN composites with different h-BN-KH560 contents and good thermal conductivity were prepared by hot pressing. The FTIR analysis confirmed the successful grafting of KH560 onto the surface of h-BN-OH. By utilizing h-BN-KH560 and GO as thermal conductive fillers, we achieved a higher thermal conductivity in the composite material, creating a “dual thermal conductivity network” compared to using a single filler. Additionally, the thermal conductivity increased as the content of h-BN-KH560 increased. At h-BN-KH560 contents of 20 wt%, 40 wt%, and 60 wt%, the thermal conductivities of the prepared PMIA/EP/GO/h-BN composites were 0.661 Wm⁻¹K⁻¹, 1.082 Wm⁻¹K⁻¹, and 1.206 Wm⁻¹K⁻¹, respectively. Importantly, the addition of the thermal conductive filler did not significantly affect the thermal stability of the composites.