Achieving Balanced Mechanical Properties and Flame Retardancy in Flame‐Retardant <scp>EPDM</scp> via Interfacial Regulation Strategy of Organic–Inorganic Hybrid Particles

ABSTRACT Ethylene propylene diene monomer (EPDM) is widely used in automotive applications but suffers from poor fire safety. Conventional flame retardants can improve flame resistance only at high loadings, which usually cause serious deterioration of mechanical properties. To overcome this trade‐off, multifunctional organic–inorganic hybrid particles (h‐BN@TAMAA) were engineered from h‐BN through interfacial regulation to provide synergistic effects. With h‐BN@TAMAA, the loading of conventional flame retardants was reduced by 37.5% while maintaining a UL‐94 V‐0 rating. Benefiting from the combined effects of increased rubber content and the reactive structure of h‐BN@TAMAA, the composites achieved a tensile strength of 14.2 MPa and an elongation at break of 418%, corresponding to only 9.5% and 10.1% losses, respectively, relative to the blank sample. Cone calorimetry further revealed improved fire safety, with peak heat release rate, total heat release, and carbon monoxide production rate reduced by 14.9%, 19.8%, and 80.0%, respectively, compared with the reference material. This work provides a practical strategy for simultaneously enhancing flame retardancy and mechanical integrity in EPDM.