Enhancing Interfacial Adhesion and Tribological Performance of Aramid Fiber/Rubber Composites via Synergistic Hydrogen-Covalent Dual-Networks.

Elucidating the physical chemistry of solid-elastomer interfaces is critical for overcoming thermodynamic incompatibility in aramid fiber/natural rubber (AF/NR) composites. Here, model interfaces governed by van der Waals forces, π-π stacking, covalent cross-linking, and a hydrogen-covalent dual-network were constructed to clarify the relationship between molecular interactions and macroscopic failure. Weak physical interactions provide limited adhesion, whereas rigid covalent bonding can induce stress concentration. In contrast, the dual-network improves surface energy and interfacial thermodynamics, promoting favorable wettability and intimate contact. Consequently, H pull-out and 180° peel forces increased by 179.05% and 155.58%, respectively. Molecular simulations further revealed a maximum binding energy of -118.34 kJ/mol. Mechanistically, covalent linkages provide stable anchoring, while dynamic hydrogen bonds facilitate energy dissipation through reversible dissociation and reconstruction under loading. This synergistic network also reduces hysteresis loss and improves stability under cyclic loading and frictional wear, providing a rational framework for designing durable AF/NR interfaces under demanding service conditions.