Preparation and properties of resin matrix composites reinforced by high thermal conductivity graphite films

Abstract

AbstractHigh thermal conductivity graphite films (GFs) have a thermal conductivity, which have attracted much attention in recent years. As the surface of GFs is extremely smooth, the resin matrix and GFs are only connected by van der Waals forces, and it is difficult to produce chemical bonds between them, resulting in poor mechanical properties of the composites. In this study, the composites were prepared by etching defects on the surface of GFs by high‐temperature heat treatment. It was determined that the critical temperature range for effective etching was between 600 and 650°C. The GFs were subjected to high‐temperature heat treatment to create circular, hexagonal, and disordered groove‐like defects, and then combined with prepregs and bismaleimide resins in a single molding process. The composites exhibit a distinct layered “sandwich” structure, where surface‐induced defects enhance the interfacial adhesion between GFs and the resin matrix, creating a “nail‐punched” structure. The thermal conductivity of the S‐650 sample in the X‐direction was up to 1187.93 W/(m·K), and the flexural strength of the S‐800 sample was up to 116.18 MPa. The prepared composites are expected to be widely used in thermal interface fields such as heat exchangers, battery heat dissipation and aerospace thermal control systems.Highlights High‐temperature treatment was used to successfully introduce defects into GFs. The formation mechanisms of the three types of defects were explained. The thermal conductivity of the composites was increased to over 1000 W/(m·K). Composites reinforced with modified GFs exhibit enhanced mechanical properties.