Sustainable and high-exhaustion dyeing for cotton fabrics using biomass-based keratin modification

Abstract

A new strategy has been designed for sustainable eco-dyeing of cotton fabric through biomass-based rabbit hair keratin modification. High dye-ability of cotton is achieved through the regulation of its surface physicochemical properties. The extracted keratin can provide substantial polar groups on the fiber surfaces, improving the binding ability of natural dyes to the cotton fabric. Additionally, the existence of aromatic amino acids in keratin enhances the UV resistance of the fabric. The optimized dyeing rate, adsorption capacity, K/S value, and UPF value of cotton fabric reach 92.0%, 25.004 mg/g, 9.1, and 57.0, respectively. Keratin modification can not adjust the surface infiltration of the fabric but does reduce the electrostatic interference during the dyeing process, which effectively increases the coloring intensity and evenness of the dyed fabrics. Theoretical calculation (DFT) indicate that introducing keratin adjusts the cellulose molecular structure, resulting in a much higher interaction energy between the modified fabric and gardenia yellow dye. The washing, soap washing fastness and chromatism (Sr) of the dyed fabric achieve grade 4, grade 3 and 0.16.