Synergistic Interfacial Reinforcement and Dynamic Mechanical Properties of Wet‐Mixed Natural Rubber/Carbon Black/Silica Hybrid Composites

ABSTRACT Tuning filler architecture and interfacial interaction is essential to optimizing the performance of advanced rubber composites. In this study, a series of functionalized carbon black/silica hybrid fillers (DCB) with distinct specific surface areas and pore size distributions were synthesized to reinforce natural rubber (NR) via a wet‐mixing process. Morphological characteristics have shown that surface functionalization effectively mitigates the agglomeration of fillers and ensures uniform distribution within the rubber matrix. Dynamic mechanical analysis and equilibrium swelling tests have revealed that the pore topology adaptable to DCB fillers promotes the formation of bound rubber and thus increases effective hydrodynamic volume. In particular, L‐DCB has a large pore (> 50 nm) and exhibits a reduced resistance module enhanced by the physical entrapment of rubber chains. On the contrary, the high specific surface area of DCB with a high specific surface area facilitates the strongest interfacial interaction. This was evidenced by a 10% increase in bound rubber content, achieving a superior tensile strength of 30 MPa and minimum volume loss (0.2 cm 3 ). Furthermore, analysis of the Payne effect supports that energy dissipation is mainly influenced by the chain desorption dynamics at the filler–matrix interface. Consequently, the low specific surface area of DCB/NR composite offers an optimal trade‐off between wet skid resistance and rolling resistance for green tire applications, while the middle specific surface area of the DCB/NR system displays the most balanced overall mechanical profile. This work emphasizes the synergy of pore structure engineering and surface modification in the design of high‐performance elastomer composites.