Investigation of Dyeing Condition for Cotton Fabric with Reactive Disperse Dye under Supercritical Carbon Dioxide

Abstract

In order to apply the supercritical fluid dyeing system to cotton fabrics, we investigated the dyeing condition of cotton fabric with reactive disperse dye under supercritical carbon dioxide (scCO₂). The reaction condition between hydroxyl groups of cotton and vinylsulfone group of reactive disperse dye was examined by using divinilsulfone as the model of dye. The attractive condition to achieve the high reaction rate between the cotton fabric and the divinylsulfone was treated with 50 mM of ethylene diamine at 120°C and 25 MPa under scCO₂. Based on this condition, the dyeing condition of cotton fabric was examined using the synthesized thiazole azo reactive disperse dye having vinylsulfone group. Although it is effective to add a small amount of water up to 3wt% on CO₂ to obtain the large dyeing depth of cotton fabric, the color fading occurred in the fabric with long time dyeing and it was therefore necessary to set the dyeing time to 4 h.