Optimization of Eco-Friendly Reactive Dyeing of Cellulose Fabrics Using Supercritical Carbon Dioxide Fluid with Different Humidity

An eco-friendly dyeing of cotton fabrics with Reactive Golden Yellow K-2RA was carried out using supercritical carbon dioxide fluid with different humidity. Effect of dyeing temperature, pressure, time, dye concentration, and gas humidity on the dyeing properties of cellulose was investigated. The results indicated that good dyeing effect was achieved because of the nucleophilic substitution reaction of monochlorotriazine reactive group in Reactive Golden Yellow K-2RA and hydroxyl functional groups in cotton. The color strength of dyed samples was improved with the variation of dyeing conditions. An optimized eco-friendly dyeing of cellulose fabrics was recommended with a dyeing temperature of 90 degrees C, a dyeing pressure of 20 MPa, a dye concentration of 5%, and gas humidity of 5% for 60 min in supercritical carbon dioxide fluid. Furthermore, acceptable washing, rubbing and light fastness rated over 4 were obtained.