Enhancing Thermal Conductivity of Epoxy Polymers via Template‐Assisted Construction of 3D Graphene Networks

ABSTRACT The low intrinsic thermal conductivity (TC) of polymers limits their application in thermal management. To address this, we developed a three‐dimensional (3D) interconnected graphene (Gr) network using a sacrificial NaCl template, which significantly enhances heat transfer pathways in epoxy composites. After epoxy resin infiltration, the resulting graphene/epoxy (Gr/EP) composite exhibited a through‐plane TC of 4.19 W/(m K) at a graphene loading of 24.32 wt%, representing a 19.95‐fold increase over pure epoxy (0.21 W/(m K)). Heating platform tests and water‐cooling experiments further confirmed the Gr/EP composite's superior thermal performance. The 3D graphene skeleton provides multiple phonon pathways, significantly reducing interfacial thermal resistance and scattering. This work presents a high‐TC Gr/EP composite and a straightforward preparation method, offering broad potential for thermal management applications.