A facile method to prepare layered solid fillers-based polymer composites with isotropic thermal conductivity

Layered solid particles such as hexagonal boron nitride (h-BN) and graphite have been employed as anisotropic thermo-conductive fillers in polymer composites. To meet the recent requisite capability of thermal interface materials (TIMs), facile methods to prepare polymer composites with isotropic thermal conductivity utilizing the layered solid fillers have been desired. We accomplished to prepare composites of epoxy and the layered solid fillers with isotropic thermal conductivity. Production of spherical composite particles followed by compression forming of them yielded the polymer composites with isotropic thermal conductivity. The solids loading of the obtained polymer composites surpassed 60 vol%. The thermal conductivity values of the prepared specimens were ∼ 8 Wm−1K−1 for the h-BN/epoxy composite and 28 ∼ 29 Wm−1K−1 for the graphite/epoxy one. The internal solid fillers configuration achieved by integration of the spheres was studied by X-ray diffraction analysis.