Recyclable Dynamic Network Composite Enables Effective Electromagnetic Interference Shielding and Thermal Management

The miniaturization and high-power density of electronic devices have rendered heat accumulation and electromagnetic radiation pollution critical bottlenecks that constrain performance enhancement and operational longevity. A critical challenge that severely restricts their applicability in flexible electronics exists due to poor filler dispersion and weak interfacial interaction in composites. Herein, we report a sustainable and multifunctional elastomer composite based on natural rubber (NR) decorated with tannic acid (TA) and reinforcing hybrid filler comprising Fe3O4-decorated reduced graphene oxide (FrGO) and TA-functionalized carbon nanotubes (TCNT). The dynamic networks were constructed in FrGO/TCNT/TNR composites through hydrogen bonding and metal–ligand coordination via supramolecular assembly, significantly enhancing the comprehensive performance of the composites. The resulting composites exhibited improved mechanical strength of 2.4 MPa and high fracture toughness (4.6 MJ/m3). Notably, the incorporation of FrGO/TCNT filler significantly improved the interfacial interactions, enabling efficient phonon transport and electromagnetic wave attenuation, achieving a thermal conductivity of 1.389 W/(m·K) and an EMI shielding effectiveness of up to 31 dB in the X-band with an absorption-dominated mechanism, increasing by 826% and 885%, respectively, compared with pure NR. Furthermore, the composites demonstrated good recyclability after multiple cycles and good EMI shielding reliability under various mechanical and environmental conditions. This work provides a scalable strategy for designing multifunctional elastomer composites for advanced applications in flexible electronics.