Enhancing Thermal Conductivity of Polymer Matrix Composite by Optimizing Filler Structure

Polymer matrix composites are widely used in thermal management due to their advantages of light weight, corrosion resistance, easy processing and low cost. However, polymers typically have low thermal conductivities, and the addition of thermal conductive fillers is the main way to improve their thermal conductivities. The filler is one of the important factors that influence the thermal conductivity of composite materials. Therefore, the effect of the intrinsic structure of the filler on the thermal conductivity of polymer matrix composites is investigated to improve the utilization efficiency of the filler. According to the research idea of “topology optimization-simplification-verification”, the topology optimization is used to obtain the best structure of thermal conductivity filler by targeting the high thermal conductivity of the composite material. On the basis of this, the structure is simplified by considering the processability, and the thermal conductivity of the composite is verified by finite element analysis and infrared thermography. Results show that the composites present the best directional thermal conductivity when the shape of the filler is a dumbbell with two larger ends and a smaller center under the same graphite volume fraction. This paper provides a new idea for the structural design of highly efficient thermally conductive fillers and a new way to study the effect of the intrinsic structure of the filler on the thermal conductivity of composites and how to improve the utilization efficiency of fillers.