Novel Method for Fast Bleaching of Cellulose Acetate Fabric by Using H2O2 Aided by Ultrasonic Waves

Abstract

This research focuses on the use of ultrasonic waves to aid ultrasonic aided hydrogen peroxide (H2O2) bleaching (UAB) of cellulose acetate fabrics. UAB is studied under different conditions and based on the results obtained, the following conditions are established: H2O2 concentration, 10g/l; reaction temperature, 30°C; reaction time, 3 min; and pH, 9.0. The bleaching effect is expressed in terms of acetyl content, loss in fabric weight, whiteness index, roughness degree, tensile strength and elongation at break when the cellulose acetate fabrics are bleached per the UAB method as well as the conventional method. A comparison between the two methods with regards to these properties reveal the superiority of the UAB method with its novelty and fast inducing bleaching under the influence of cavitations and extra energy generated thereof; the cavitations are caused by the high frequency of the ultrasonic waves. Electron scanning microscopies of the UAB bleached fabric display a smooth and partially swollen surface morphology opposite those of conventionally bleached fabric in which the surfaces are irregular, rough and scratched bleached. In addition, UAB bleached fabric displays a significantly higher dyeability towards disperse dyes than the untreated fabric and fabric bleached by using the conventional method.