Thermal conductivity of polyaniline reinforced epoxy resin

This study introduces the possibility of using polyaniline as a thermally conductive filler in the manufacturing process of composites using epoxy. Compared to conventional thermally conductive fillers, polyaniline is a material with a simple synthesis process and is cost-effective. In this experiment, among various types of polyaniline, polyaniline in the form of an emeraldine salt (ES) doped with protons and polyaniline in the form of a dedoped neutral emeraldine base (EB) were used as the thermally conductive filler. ES doped with protons show higher electrical and thermal conductivity than EB due to the conductive polymer characteristics in which the thermal conductivity increases as the electrical conductivity increases. We put both fillers into the widely commercially available diglycidyl ether of bisphenol A (DGEBA) epoxy composite, and analyzed the effect of the thermal conductivity of the filler increased by doping on the thermal conductivity of the composite, and analyzed the possibility of use as a thermally conductive filler. The epoxy resin without filler was measured to have the thermal conductivity of 0.21 W/m K, the thermal conductivity of the composite reinforced with EB filler was measured to be 0.27 W/m K, and the thermal conductivity of the composite reinforced with ES filler was measured to be 0.29 W/m K. The results confirmed that the input of polyaniline as a thermally conductive filler could improve the thermal conductivity of the composite, and also confirmed that the proton-doped ES filler showed higher thermal conductivity than the neutral EB filler. Through this study, we highlight the possibility that polyaniline can be used as a promising thermally conductive filler for various composite materials.

Graphical abstract

Proton-doped polyanilines, when used as thermally conductive fillers in epoxy composites, increase thermal conductivity more effectively than dedoped polyanilines