Design Strategies for Thermally Conductive Polymer Composites Based on Interface and Network Engineering

ABSTRACT Thermally conductive polymer composites are essential materials for thermal management in advanced electronic, energy, and packaging systems, yet their performance is fundamentally constrained by interfacial thermal resistance and discontinuous heat‐conduction pathways. While ceramic fillers such as aluminum nitride and boron nitride provide electrical insulation and high intrinsic thermal conductivity, simply increasing filler loading often leads to poor processability and limited thermal gains. In this review, we systematically summarize recent design strategies for thermally conductive polymer composites, with a particular focus on interface engineering and network engineering as two complementary and interdependent approaches. Surface modification methods—including silane coupling, polymer grafting, and bio‐inspired non‐covalent coatings—are discussed in terms of their roles in enhancing interfacial adhesion, improving dispersion stability, and mitigating phonon scattering. Beyond interface chemistry, structural engineering strategies such as hybrid filler systems, controlled alignment, and hierarchical size–dimension design are examined for their ability to promote continuous and directional heat‐transport pathways. Special emphasis is placed on pre‐constructed three‐dimensional thermally conductive networks, which effectively lower percolation thresholds and enable high thermal conductivity at reduced filler contents. By integrating insights from interfacial chemistry and network topology, this review provides a unified design framework that clarifies structure–property relationships and offers guidance for the development of next‐generation thermally conductive polymer composites for practical thermal management applications.