Core-shell structured BN/PPS composite film for high thermal conductivity with low filler concentration

Abstract BN/PPS core-shell structured pellet and its composite film were primarily fabricated via a particle coating method using an adhesive layer. A thermally conductive composite was fabricated using BN-coated PPS by hot pressing. The core-shell structure did not collapse after hot pressing and formed a well-connected particle chain. Moreover, the BN/PPS composite prepared using the proposed method has a higher thermal conductivity compared to the conventional composite fabrication method, melt mixing and powder mixing, at the same filler concentration because the connected particle chain acts as a continuous heat flow channel. Moreover, the thickness of the particle layer can be controlled by controlling the viscosity of the adhesive epoxy layer using acetone as the solvent. We fabricated BN/PPS pellets with various BN layer thickness. A 1:0.3 wt ratio of epoxy and acetone has the highest thermal conductivity enhancement ratio compared to the melt mixed composite. We fabricated a composite using the hybrid method; the polymer core was prepared via melt mixing and the BN particles were coated on this core. The BN particle in the core and the outer layer has a synergetic effect, forming a 3-dimensional heat flow path, leading to outstanding thermal conductivity with a only small amount of filler.