Ultra-high thermal conductivity and mechanical properties of a paraffin composite as a thermal conductive phase change materials for novel heat management

Because of their large latent heat, phase change material (PCM) composites have received much attention for thermal energy storage and heat management applications. However, the intrinsically low thermal conductivity of PCMs remains a challenge for efficient heat management. In this study, a mixed matrix composed of stearic acid-grafted bisphenol A (SABPA) and paraffin was filled with a porous expanded graphite network impregnated with alkylated boron nitride; the resulting composite showed an ultrahigh through-plane thermal conductivity of 7.21 W/mK, mechanical property (tensile strength and elongation at break) improvements of 470 and 568% compared to pure paraffin, and a latent heat of 93.506 J/g. When the PCM composite was applied in electrical devices, we observed heat buffering caused by the large latent heat of PCM, in contrast with existing conductive polymer composites. This novel thermal management approach, combining heat storage and heat dissipation, makes the SABPA/paraffin composites promising materials for thermally conductive PCM composites and advanced electronic packaging.