Biomass Waste-Derived Chitosan/Sacred Lotus Leaf Wax Composite Biocoating for Water-Resistant Cotton Fabrics

A sustainable water-resistant coating based on a chitosan/sacred lotus leaf wax composite was developed and deposited onto cotton fabrics using a simple dip–dry–cure process. The effect of the chitosan-to-sacred lotus leaf wax weight ratio on the surface wettability, air permeability, water vapor permeability, mechanical properties, and laundering durability of the coated fabrics was systematically investigated. The incorporation of sacred lotus leaf wax significantly enhanced the hydrophobicity of the cotton fabrics, with the highest water contact angle (WCA) of 167.12° achieved at a chitosan-to-wax weight ratio of 7:3. Although increasing the wax content improved water repellency, it also resulted in slight reductions in tensile strength, air permeability, and water vapor permeability. After 20 home-machine washings, the coated fabric retained a WCA of 137.11°, demonstrating good laundering durability. These results demonstrate that the chitosan/sacred lotus leaf wax composite is a biodegradable, non-toxic, and environmentally friendly alternative to conventional water-repellent finishes, offering considerable potential for the development of sustainable functional textile coatings.