Sustainable Cotton Dyeing with Banana Floral Stem Extract Using Microwave Irradiation and Chitosan Optimised by Response Surface Methodology

Natural dyes offer a sustainable alternative to synthetic dyes, addressing environmental concerns in textile production. Currently, the dyeing and finishing stages typically consume large amounts of water, energy, and chemicals. A microwave-assisted dyeing process using chitosan and banana floral stem extract has been developed for cotton fabrics to enhance sustainability. This process was optimised using Response Surface Methodology and Box-Behnken Design to minimise lightness and maximise colour difference. The optimal conditions include a radiant power of 554.12 W, radiation time of 7.10 min, and chitosan concentration of 0.80%. These conditions result in a lightness value of 62.04, a colour difference of 35.36, and a desirability coefficient of 0.856. Cotton samples treated under such conditions exhibited superior colourfastness compared to conventional methods, with ratings of 4 (good) for washing, 4-5 (good to excellent) for lightfastness, and 4-5 (good to excellent) for perspiration. The colourfastness scale ranges from 1 (very poor) to 5 (excellent), indicating the level of resistance to fading or colour change. The study demonstrates the eco-friendly and efficient potential of microwave-assisted dyeing with chitosan, promoting sustainable textile practices