Mechanical and water absorption behavior of hybrid epoxy composites reinforced with human and goat hair fiber

This study is on mechanical performance and water absorption behaviour of hybrid epoxy composites reinforced with human hair and goat hair fiber. The composites were fabricated using a compression molding technique. Three formulations were developed by maintaining a constant epoxy content of 70 wt.% while varying the reinforcement ratios of human hair (25, 22, and 20 wt.%) and goat hair (5, 8, and 10 wt.%). Mechanical properties were evaluated through tensile strength and microhardness tests, while water absorption tests were conducted to assess moisture resistance. The results show that the composite containing 20 wt.% human hair and 10 wt.% goat hair exhibited the highest tensile strength (13.42 MPa) and hardness (29.4 HV), along with the lowest water absorption (∼2.19%). SEM observations revealed improved fiber–matrix adhesion, uniform fiber dispersion, and reduced void content in the optimized composite. Statistical analysis (ANOVA) confirmed significant differences among the compositions (p<0.001), while regression analysis demonstrated a strong positive correlation (R ² >0.90) between goat hair content and mechanical properties. Furthermore, all samples exhibited low moisture uptake (<3% after 24 h), indicating good dimensional stability. The findings suggest that hybridization of human and goat hair fibers provides a sustainable approach for developing lightweight composite materials with enhanced mechanical performance and moisture resistance.