Interfacial Networks Engineering Towards Recyclable, Highly Thermally Conductive and Mechanically Robust Natural Rubber Composites

ABSTRACT The urgent demand for recyclable thermal interface materials (TIMs) in high‐power electronics necessitates elastomers that reconcile highly thermal conductivity, mechanical resilience, and sustainability. Herein, we report natural rubber (NR) nanocomposites synergistically integrated with polyrhodanine‐coated carbon nanotubes (PCNT) and Fe 3+ ‐decorated reduced graphene oxide (rGO‐Fe) via dynamic interfacial networks with glutamic acid‐functionalized NR (GNR). Multiple interfacial networks composed of Fe 3+ ‐carboxyl ionic coordination, hydrogen bonding between GNR and PCNT/rGO‐Fe, and covalent grafting of PCNT on GNR were engineered to bridge fillers and the matrix, enabling the highly thermal conductivity, mechanical robustness, and recyclability. The nanocomposites achieved exceptional mechanical properties (tensile strength: 3.57 MPa, elongation at break: 532%) and highly thermal conductivity of 2.29 W/(m·K), outperforming most reported NR‐based composites. The dynamic interfacial networks promoted efficient energy dissipation and phonon transfer, resulting in maintaining good mechanical properties, reprocessability, and highly thermal conductivity even after recycling. This work resolves the critical trade‐off between thermal, mechanical, and recyclable properties of sustainable elastomers through interfacial engineering. The developed NR‐based TIMs may open up new possibilities for next‐generation electronic devices in thermal management fields.