Sustainable Chitosan Biomordant Dyeing and Functionalization of Cotton Fabrics Using Pomegranate Rind and Onion Peel Extracts

A sustainable one-bath dyeing and functionalization process of cotton fabrics with pomegranate rind and onion peel extract using chitosan (CS) biomordant was investigated. Liquid chromatography-mass spectrometry was used to verify the presence of the main colorants, ellagic acid and quercetin, in the prepared extracts of pomegranate rind and onion peel. CS mordanting improved the color strength and wash fastness of pomegranate rind and onion peel dyed fabric by up to 36% and half a rating point, respectively. CS significantly enhanced the UV protection (UPF 50+) and antimicrobial activity (ranges from 93.8 to 99.9%) of dyed fabric. Chitosan mordanting improved the bending rigidity and compression recovery of the cotton fabric, but it also reduced the handle and flexibility of the treated fabrics owing to the formation of CS layer on the cotton fabrics. The dyed fabric also showed remarkable deodorizing (above 80%) and antioxidant (above 90%) properties. Overall, the proposed process could be a sustainable and economical alternative to the conventional metal mordant process.