Interfacial Reinforcement of EPDM Composites via Electron-Beam Irradiation: Synergistic Improvement in Mechanical and Ablation Performance

In this study, high-energy electron beam irradiation was strategically employed to modify the interface of the aramid fibers. Systematic investigation revealed that controlled irradiation doses produced dual surface enhancements: simultaneous generation of reactive functional groups and nanoscale topological restructuring. These synergistic modifications effectively improved the interfacial adhesion with EPDM rubber matrices. The optimized coirradiation protocol with epichlorohydrin demonstrated superior performance, achieving remarkable enhancements of 154% in H-pullout force and 30% increase in tensile strength of EPDM composites. Advanced characterization through low-field NMR coupled with in situ electron microscopy analysis elucidated the dynamic interfacial bonding mechanism and its direct correlation with macroscopic mechanical properties. Furthermore, the strengthened interface was found to facilitate carbon layer evolution during ablation, enabling the formation of denser adiabatic carbon structures that reduced the mass ablation rate by 21%. This radiation-induced interfacial engineering approach presents a scalable pathway for manufacturing high-performance flexible composites, successfully addressing the long-standing challenge of balancing mechanical robustness with thermal protection requirements in aerospace applications.