Dielectric constant and breakdown strength of polymer composites with high aspect ratio fillers studied by finite element models

A finite element model was used to study the dielectric constant and breakdown strength of polymer composite filled with high aspect ratio fillers. The impact of composite microstructure and filler aspect ratio on the dielectric properties was investigated. The results were used to explain the experimental data for BaTiO3 fiber filled poly(dimethyl siloxane) published previously. The effect of filler shape, aspect ratio distribution, curvature, grain boundary and alignment on the composite permittivity was studied. A model was proposed to correlate the composite microstructure, the electric field distribution in the polymer matrix, and the dielectric breakdown strength of composites.