Investigation of Hardness, Microstructure, and Mechanical Properties of Goat Horn Powder–Reinforced Wood-like Polyurethane Composites

This study investigates the effect of goat horn powder (GHP) reinforcement on the hardness, microstructure, and mechanical properties of wood-like polyurethane composites. GHP, a keratin-based animal waste, was incorporated into the polyurethane matrix at weight fractions of 5, 10, 15, 20, and 25 wt.%. The mechanical behavior was evaluated through tensile, three-point bending, Charpy impact, and Shore D hardness tests, complemented by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses. Results indicate that GHP significantly enhances impact resistance, with 10 wt.% loading achieving a 140% improvement in impact energy compared to the neat matrix. Tensile stress improved by 12.89% at 5 wt.% loading. However, reinforcement levels exceeding 10-15 wt.% led to a decline in tensile and flexural performance due to particle agglomeration and weak interfacial adhesion. Shore D hardness increased systematically with higher GHP content across all ratios. The study demonstrates that GHP is a functional, sustainable reinforcing element that improves toughness and hardness while supporting environmental waste management.