This manuscript presents an integrative, theory-driven, and synthesis-oriented examination of biodegradable natural-fiber reinforced polymer composites with particular emphasis on two convergent application domains: antimicrobial packaging and structural components. The aim is to weave together established experimental results, mechanistic explanations, and theoretical perspectives drawn from recent reviews and primary studies in order to propose a cohesive conceptual framework that explains how fiber selection, surface modification, matrix chemistry, and processing interact to determine mechanical performance, thermal stability, hygroscopic aging, and antimicrobial functionality. The paper synthesizes evidence showing that biodegradable matrices such as polylactic acid (PLA) combined with lignocellulosic reinforcements—kenaf, bamboo, cellulose nanofibers—can be engineered to deliver acceptable structural stiffness and strength while offering end-of-life advantages and functional antimicrobial barriers when functional additives or active agents are appropriately integrated (Kamarudin et al., 2022; Nurazzi et al., 2021). Thermal analyses (TGA/DSC) reveal how fiber loading, interfacial adhesion, and plasticizer use alter degradation onset and glass transition behaviour, which in turn govern service temperature envelopes and processing windows (Nurazzi et al., 2022). Hygroscopic aging and moisture-induced performance decay are traced to fiber cell wall composition and interfacial microstructure; chemical modifications and compatibilizers mitigate but do not fully eliminate long-term moisture uptake (Mokhothu & John, 2015). The paper advances a set of mechanistic hypotheses for the dynamic mechanical behaviour of viscoelastic natural-fiber composites and outlines a set of prioritized research gaps: standardized accelerated aging protocols, life-cycle informed mechanical design rules, scalable antimicrobial agent integration compatible with composting, and multi-scale modelling linking microstructure to macroscopic durability (Shlykov et al., 2022; Espinach, 2021). The discussion critically appraises trade-offs between sustainability and performance and offers a roadmap for future experimental programs and standardization efforts.

natural fiber composites, biodegradable polymers, antimicrobial packaging, polylactic acid (PLA)

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