Molecular simulation study on thermal and mechanical properties of polypyrrole/graphene nanocomposite

Polymers have many ideal physical properties but low thermal conductivity (TC) limits their application. Filling polymers with thermal conductive fillers is the main strategy used today. Polypyrrole (PPy) and graphene (GE) are used to design a special thermal conductive polymer nanocomposite in our work. TC and mechanical properties of PPy/GE nanocomposites are studied using Molecular Dynamic (MD) and Non-Equilibrium Molecular Dynamic (NEMD) methods. Notably, the incorporation of GE as a thermal conductive filler in PPy results in substantial improvements in both TC and mechanical properties. The TC of the PPy/GE nanocomposite reaches up to 0.256 W m-1 K-1, which is 55% higher than that of pure PPy. The ultimate strength reaches a peak value of 0.278 GPa; while, the average Young's modulus increases about 33.17%. It is suggested that a GE doping content range of 5.5-8.7% is recommended for improving TC and mechanical properties of PPy/GE. It shows significant potential of PPy/GE nanocomposite in thermal conductive materials and insights for the development of modified PPy for thermal interface and packaging materials.