Modeling the thermal conductivity of epoxy/POSS and Epoxy/POSS/cBN composites

Epoxy-based insulating systems usually feature a low thermal conductivity, which is a limiting factor for application in high voltage apparatus. Improved properties such as thermal conductivity, breakdown strength or resistance to erosion from corona discharges can be obtained by replacing the neat epoxy with composite systems reinforced by inorganic particles. Particularly interesting fillers are Polyhedral Oligomeric Silsesquioxanes (POSS) with reactive side-groups that can be dispersed at the nanometric level up to a high filler rate and that have been shown to improve the dielectric properties of the resulting composites as well as their thermal conductivity. The aim of this paper is to present a model able to predict the thermal conductivity of epoxy/POSS based composites. The proposed model was validated by Finite Elements Method (FEM) simulations.