Low temperature bleaching of cotton cellulose using peracetic acid

In this study peracetic acid was prepared by the reaction of hydrogen peroxide with glacial acetic acid in the presence of concentrated sulfuric acid as a catalyst. Factors affecting peracetic acid formation were studied, together with following up the amount of residual hydrogen peroxide and amount of converted peracid throughout the reaction period. The so prepared peracetic acid was used for bleaching cotton fabrics, and different variables affecting the bleaching process were extensively studied. The bleached fabrics were fully characterized and results obtained show that optimum conditions for bleaching were using peracetic acid at concentration of 40 ml/l at 70 °C, using a material to liquor ratio of 1:30 at pH 6 for 30 min and then turning the pH to 10.5 and continuing bleaching for extra 30 min. These conditions were found to give bleached fabric with satisfactory whiteness index with reasonable loss in tensile properties.