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 BoxBehnken 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 ecofriendly and efficient potential of microwave-assisted dyeing with chitosan, promoting sustainable textile practices.