Effect of fish scale-derived biofiller loading on the mechanical, microstructural and moisture-resistance behavior of snake plant fiber/epoxy composites

), attributed to effective fiber-matrix interaction and matrix continuity. Increasing FS content caused a gradual decline in tensile, flexural, and impact properties, particularly at higher filler loadings, due to weakened interfacial adhesion and increased defect formation. However, hardness improved with FS incorporation, reaching a maximum value of 72.54 Shore D at 10 wt% FS. SEM analysis revealed a transition from rough, well-bonded fracture surfaces to brittle, crack-dominated morphologies with increasing filler content, while FTIR indicated physical interactions without new chemical bonds. At 120 h, water absorption decreased by 36%, from 17.50% in S1 to 11.20% in S5. However, apparent diffusion coefficients showed no consistent trend, indicating reduced moisture retention but not necessarily slower transport. Overall, 5-10 wt% FS provided the best performance balance, although long-term moisture durability requires further validation. These findings support the development of lightweight, sustainable composites for non-load-bearing and semi-structural applications.