Research gaps and emerging trends in banana fiber-reinforced composites: A scoping review

This review systematically maps existing research on banana fiber-reinforced composites (BFRCs) to identify performance trends, methodological variations, and critical knowledge gaps. Analysis of over 112 studies published between 2020 and 2025 shows that alkaline treatment (5-10% NaOH) improves tensile strength by 15-42%, while silane treatment enhances interfacial bonding by up to 30%. Most matrices used are polypropylene, epoxy, and PLA, with optimal fiber loadings reported between 20-40 wt%. Mechanical performance trends indicate tensile strengths ranging from 45-210 MPa, depending on fiber treatment, orientation, and processing technique. However, only a few studies assess long-term durability, and fewer than 5% report standardized testing protocols. Thermal stability generally improves by 8-25% after chemical modification, yet biodegradability and life-cycle performance remain underexplored. Evidence mapping reveals significant gaps in scalability, moisture resistance optimization, fiber-matrix compatibility with biodegradable polymers, and industrial-grade process standardization. The study provides a structured framework for guiding future BFRC research and highlights opportunities for advancing high-performance, sustainable composite materials aligned with circular economy goals. • Provides the first structured scoping review on banana fiber reinforced composites. • Maps existing research gaps, including limited standardization, durability studies, and scalability issues. • Identifies emerging trends in hybrid composites, surface treatments, and biodegradable matrices. • Demonstrates the potential of banana fibers as a sustainable alternative for waste valorization and circular economy applications. • Offers future research directions to guide material scientists and policymakers.