Heat transfer mechanism in graphene reinforced PEEK nanocomposites

The thermal conductivity of graphene is in the range of 3000-5000 W m^-1 K^-1, showing great potential in high thermal conductivity devices. However, the thermal conductivity of graphene-reinforced polymer is typically lower than 10 W m^-1 K^-1, which is far from theoretical expectations. To understand the mechanisms of heat transfer in graphene-reinforced polymers, this work investigated the effect of graphene addition on the thermal conductive performance of polyetheretherketone (PEEK) matrix. The study examined the number of layers, deflection angles, and interlayer distances using molecular dynamics (MD) simulations. The results showed that the improvement of thermal conductivity of PEEK nanocomposite was not only related to the content of graphene but also to the angle between the benzene ring in the molecular chain of PEEK and the transfer direction of heat flow. Increasing the number of graphene layers is more beneficial to the enhancement of thermal conductivity. In particular, the enhancement of thermal conductivity is most significant when the number of graphene layers is the same, and the interlayer distance is less than the truncation radius.