Graphite coatings by soybean oil epoxide (ESO) on PA6 particles for substantially enhanced thermal conductivity via constructing segregated filler networks

Recently, the demand for thermal management has become increasingly high with the continuous advancement of electronic devices. Thermally conductive polymer composites are gaining more attention as the potential next‐generation thermal conductive materials. However, challenges remain, especially the low thermal conductivity (TC) of conventional polymers, which limits their use in devices needing efficient heat dissipation. This paper presents the preparation of Polyamide 6 (PA6) particles coated with graphite to significantly enhance TC by constructing segregated filler networks, using soybean oil epoxide (ESO) as the binder. When the mass ratio of PA6 to ESO is 8:1 and the graphite content is 25 wt%, the TC of the PA6/graphite composite reaches 4.78 W/m K, which is 14 times higher than that of pure PA6. The significant enhancement is attributed to the introduction of graphite and ESO, which improves the graphite coverage on the surface of PA6 particles, thereby establishing a more effective three‐dimensional segregated TC network. Moreover, during the compression molding process, the epoxy groups in ESO react with the amino and carboxyl groups on PA6, preventing ESO from forming a separate phase within the composite and improving the compatibility of the material. This study provides new insights into high TC composites. Highlights Graphite and ESO create a segregated filler network for better heat transfer. Enhancing thermal conductivity compared to the original PA6. Maintaining excellent processing and mechanical properties.