Bleaching of cotton fabric with tetraacetylhydrazine as bleach activator for H2O2.

Tetraacetylhydrazine (TH) as bleach activator for H2O2 cotton bleaching was synthesized and characterized by 1H NMR, 13C NMR and MS spectra. TH has better solubility than that of TAED. The CIE whiteness index (WI), H2O2 decomposition rate and bursting strength were employed to investigate the performance of H2O2/TH bleaching system. By addition of TH, WI and H2O2 decomposition rate increased significantly at 70 °C. Bleaching temperature, NaHCO3 concentration and bleaching time were also discussed in detail and the loss of bursting strength is not clear. By using benzenepentacarboxylic acid (BA) as a fluorescent probe for hydroxyl radical detection, the bleaching process of H2O2/TH system was investigated. Acetylhydrazine and diacetylhydrazine were also utilized to further confirm the process. In addition, bimolecular decomposition was investigated by using 9,10-dimethylanthracene (DMA) as fluorescent probe of 1O2. Based on these experimental results, the bleaching mechanism of H2O2/TH system was proposed.