Key points are not available for this paper at this time.
Abstract Plant-based natural fiber-reinforced polymer composites (NFRPCs) have attracted increasing attention as sustainable alternatives to conventional synthetic composites due to their low density, renewability, and reduced environmental impact. However, their broader adoption remains limited by challenges related to moisture sensitivity, interfacial incompatibility, and variability in mechanical performance. This review provides a comprehensive and critical analysis of recent advances in NFRPCs, with particular emphasis on the underlying structure–property relationships governing mechanical and tribological behavior. Key factors influencing composite performance, including fiber type, morphology, surface modification, fiber content, and matrix selection, are systematically evaluated, highlighting the complex interplay between interfacial bonding, dispersion, and processing conditions. Special attention is given to the role of microstructural features in controlling load transfer, crack propagation, and wear mechanisms, thereby establishing a direct linkage between morphology and macroscopic performance. Emerging strategies for enhancing NFRPC performance are further discussed, including nanofiller integration, advanced interface engineering, data-driven modeling, and additive manufacturing. These approaches enable improved mechanical strength, thermal stability, and multifunctionality, while also offering pathways for accelerated materials design and optimization. Despite significant progress, critical challenges remain, including the lack of standardized design frameworks, limited understanding of long-term durability, and insufficient integration of multiple material parameters. This review, therefore, outlines future research directions focused on developing predictive, design-oriented frameworks that integrate microstructural engineering, advanced characterization, and computational modeling. Overall, this work provides a unified perspective on the development of next-generation NFRPCs, emphasizing the transition from descriptive material studies toward predictive, high-performance, and sustainable composite design.
Shifa et al. (Mon,) studied this question.