| Abstract Scope |
The fiber–matrix interface plays a fundamental role in determining the mechanical performance, durability, and long-term reliability of natural fiber-reinforced polymer (NFRP) composites. This review presents a comprehensive assessment of recent advances in interfacial engineering, emphasizing surface modification techniques, adhesion mechanisms, and multiscale characterization methods. The effects of alkali, silane, acetylation, plasma, and emerging bio-inspired treatments on fiber surface chemistry, wettability, and interfacial bonding are critically discussed. Recent characterization techniques, including scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and mechanical interfacial tests, are compared to establish correlations between interface quality and composite performance. Current challenges, including moisture sensitivity, interface degradation, and processing variability, are analyzed together with future perspectives involving nanostructured interfaces, bio-based coupling agents, hybrid reinforcements, and data-driven material design. This review provides guidelines for developing high-performance and sustainable biocomposites through improved interfacial engineering. |