Analytic modeling for the anisotropic thermal conductivity of polymer composites containing aligned hexagonal boron nitride

Polymer composites containing two-dimensional hexagonal boron nitride (h-BN) can achieve enhanced thermal conductivity (TC), and such enhancement is more pronounced along the orientation direction of h-BN platelets. In this paper, an analytical model was developed for simultaneously calculating the anisotropic TC of polymer composites containing aligned h-BN platelets. A unit cell was first abstracted based on the morphological observation in the literature. Then the thermal resistance method and coordinate transformation were used to derive the TC of the composites. The model was successfully validated by the experimental data from two independent literature studies over a large range of filler contents. The dependence of TC on the key parameters of the model, including the orientation angle and geometric dimension of the h-BNs, and the interfacial thermal resistance, were quantitatively analyzed and discussed.