Three-dimensional carbon fiber-graphene network for improved thermal conductive properties of polyamide-imide composites

Abstract

Thermal conductive polymer matrix composites are becoming more widely used in modern electronic devices. However, the dispersion of the filler in the composite material limits the improvement of its heat dissipation performance. In order to solve the problem, we prepared polyamide-imide composites with three-dimensional (3D) carbon fiber-graphene network. The network is built by braided frame of carbon fiber felt and the hydrogen bonding between carbon fiber and graphene oxide. When the amount of filler is 4.25 wt%, the vertical thermal conductivity (TC) of composites reaches 0.53 W m−1 K−1, which is 165% higher than that of pure PAI. The improvement of TC is mainly attributed to the following factors, for example, 1) the 3D carbon fiber-graphene network structure was established to construct the heat conduction path in the composite material; 2) the interaction between fillers reduced contact thermal resistance; 3) the introduction of oxygen-containing functional groups adversely affected the TC of the composite. Meanwhile, the tensile strength of the composites reaches 34.1 MPa and the Young's modulus is 1.2 GPa. The composites can be used as a heat sink for next-generation electronic devices.