Electrothermal Behavior of Conductive Polymer Composite Heating Elements Filled with Ceramic Particles

摘要

In this study, the influence of ceramic powders on the electrical and thermal behavior of biphasic conductive polymer composites when subjected to electrical potential difference is investigated by means of experimental measurements and modeling. The biphasic materials studied are blends of a thermal conductive polymer phase (syndiotactie polystyrene filled with aluminum oxide or boron nitride) with an electrical conductive polymer phase (high-density polyethylene filled with carbon black) in a cocontinuous structure. The thermophysical characteristics of the biphasic materials were measured as a function of temperature. This thermophysical characterization showed that the thermal conductivity of conductive polymer composites is doubled when filled with a 20% volume of ceramic powder. Ohmic heating experiments were performed on extruded tapes. A two-dimensional finite element model has been developed to determine the thermal and electrical behavior of these devices. The numerical and experimental results correlated well, which shows the relevance of adding aluminum oxide or boron nitride in the biphasic materials studied to enhance thermal conductivity of biphasic conductive polymer composites without modifying the electrical conductivity.