A comprehensive study on enhancing effective thermal conductivity of polymer composites with randomly distributed triple fillers

Abstract

This paper describes a comprehensive study on the effective thermal conductivity (ETC) of triple-filled polymer composites. A very complicated behavior was revealed under various effective factors, such as thermal conductivity (TC), volume fraction (VF), particle distribution, particle size, and filler arrangement. Consequently, some prediction models, which were well validated with numerical results, are first developed. Additionally, the ETC of polymer composite dramatically and non-linearly depends on TC ratios, VF ratios, particle distribution, filler arrangement, and particle size of the triple filler. The mountain shape of the ETC forms and depends on a variety of effective factors. The maximum ETC exists at the given optimum TC ratios ranging from approximately 0.1 to 100. It was also found that the ETC increases with the increase of the VF ratio for a threshold TC ratio; however, this trend changes when TC ratios go beyond the threshold values. Particularly, the ETC of the particle-filled polymer composite also depends on the filler arrangement, even though particles are straightly arranged along the direction of thermal flow. This effect becomes more significant when the difference in VF and TC between particles is larger. The results obtained are very useful in enhancing and maximizing the ETC of polymer composites with triple fillers and even multiple fillers in general.