Pages 431–435
Abstract
Research summary supplied by the authors
The leather sector constitutes a cornerstone of the global fashion industry; however, the management of solid waste remains a critical barrier to environmental sustainability. Specifically, tannery hair waste—a keratin-rich byproduct of enzymatic dehairing— represents a significant volume of biomass often destined for landfill. Concurrently, the industry relies heavily on commercial casein binders for glaze finishing, a practice constrained by high costs and supply chain sustainability issues. In alignment with the “waste-to-wealth” paradigm, this study engineers a high-value keratin hydrolysate binder derived directly from hair waste to functionally replace casein from leather finishing system. The extraction process was optimized to maximize protein recovery, and the resulting hydrolysate was characterized using nuclear magnetic resonance (NMR) and fourier transform infrared spectroscopy (FTIR), confirming the structural integrity of the polypeptide chains. Thermal stability was analysed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), which confirms the compatibility of keratin hydrolysate for hightemperature finishing processes. Comparative benchmarks revealed that keratin-finished leathers met all standard industry norms for grain distension, finish adhesion, and rub fastness. Notably, binder significantly outperformed commercial casein in aesthetic and functional metrics, demonstrating superior gloss intensity, enhanced hydrophobicity, and water vapor permeability. By substituting casein with a waste-derived alternative, this research successfully demonstrates a process circularity in the leather finishing system. This approach not only mitigates the environmental footprint of tannery effluent but also establishes a cost-effective, circular economy model for the leather finishing system.