An Efficient Method for Promoting Interfacial Adhesion of Cotton Fiber/Rubber Composite Using Chemical Surface Modification: From Molecular Simulation to Experiment

ABSTRACT Fiber‐reinforced damping composites exhibit viscoelastic behavior, combining superior damping properties with enhanced stiffness. However, the physical and chemical differences between cotton fibers (CF) and hydrogenated nitrile butadiene rubber (HNBR) result in weaker interfacial performance. To improve the interfacial compatibility and adhesion, HNBR was chemically modified using maleic anhydride and benzoyl peroxide. Using isophorone diisocyanate as an intermediate coupling agent, we systematically investigated the interfacial modification mechanism governing the interaction between CF and HNBR. The proposed interfacial enhancement strategy was first investigated for feasibility and effectiveness using molecular dynamics simulations, which predicted the optimal interactions between the fiber surface and HNBR chains. Compared with unmodified composites, the modified system exhibited a 36.67% increase in shear pull‐out strength. Microscopic characterization, including scanning electron microscopy, X‐ray photoelectron spectroscopy, and Fourier‐transform infrared spectroscopy, confirmed the successful modification. Pull‐out test of H‐shape specimens and in‐plane shear strength tests further demonstrated that fiber‐rubber interfacial adhesion improved by 105% and 87.66%, respectively, relative to the unmodified system. Collectively, these multiscale analyses clarify the role of isophorone diisocyanate in coupling HNBR with CF, providing both theoretical and experimental support for the design of advanced fiber‐reinforced damping composites.