Surface-reactive nanocomposite approach for improving thermal stability and flame retardancy of ethylene propylene diene monomer rubber

Ethylene propylene diene monomer rubber (EPDM), celebrated for its superior weatherability, chemical resistance, and elasticity, is widely used in seals, automotive parts, and construction. However, its performance under extreme conditions like high-frequency loads and heat is limited by poor thermal conductivity, energy loss, and rapid degradation. Therefore, enhancing its high-temperature flame retardancy and thermal stability is critical to expanding its use in advanced fields such as high-power electronics and thermal management systems. This work fabricated a surface-modified reactive boron nitride hybrid nanoparticle (h-BN-APVAC) that promoted the formation of high-quality char layers in EPDM during combustion. Additionally, it enhanced the thermal stability of EPDM through dynamic thermal exchange-mediated crosslinking of its sulfur network via h-BN nanosheets. Compared to pure EPDM, the material exhibited significant reductions in heat release rate, total heat release, and total smoke production by 37.5 %, 37.0 %, and 46.1 %, respectively. Furthermore, the hybrid demonstrated high retention of mechanical properties under prolonged high-temperature aging, confirming the efficacy of h-BN-APVAC in reinforcing the thermal stability of EPDM. Overall, this study established a high-performance flame-retardant EPDM system, providing a foundational material solution for applications in extreme environmental conditions.