Preparation Of Hydrogen Peroxide Bleaching Catalyst And Its Application In Cotton Fabrics

The traditional cotton fabric bleaching is carried out at high temperature and high p H value, which is not conducive to energy conservation and environmental protection. In this thesis, a hydrogen peroxide bleaching catalyst for cotton fabrics was self-made, and then it was applied to cotton fabric bleaching to reduce the bleaching temperature and p H value of the float solution, thus to achieve the purpose of energy saving and reducing consumption and reducing environmental pollution.In this paper, a metal protein complex was prepared by using gelatin protein and copper sulfate as raw material. It was used in the bleaching process of cotton fabric as a catalyst for hydrogen peroxide, then the process conditions for the preparation of hydrogen peroxide bleaching catalyst was optimized by determining the whiteness and capillary effect, it is :m(gelatin protein):m(copper sulfate)=25:1, adjusting the the solution p H value to 11 by Na OH, stirring until smooth at room temperature, and get the gelatin protein complexes.The results showed that the suitable dosage of the metal protein complexes can be used to improve the effect in the bleaching process of cotton fabric, the effect of additive amount, hydrogen peroxide dosage, temperature, p H value, processing time and other factors on the bleaching of cotton fabric were studied by single factor experiment, and the bleaching process of cotton fabric under the new hydrogen peroxide bleaching system was optimized. That is: metal protein complexes 2g/L, 30%H2O210m L/L, penetrating agent JFC 1g/L, scouring agent 0.2%(omf), bleaching 20 min at 70℃, and then 4 g/L sodium silicate was added, preserved for 30 min.It can be seen that the cotton fabric can obtain good bleaching effect at low temperature of 70℃under the effect of bleaching catalyst. The whiteness of the fabric has basically reached the white degree of the traditional high temperature bleaching fabric, and fabric damage decreased significantly. At the same time, the amount of alkali in the process of bleaching was decreased. So the bleaching catalyst has obvious advantages applied in cotton fabric bleaching process, it is in line with the requirements of energy saving and environmental protection.The application mechanism of the additive in cotton fabric bleaching was discussed. Results showed the metal protein complexes can be dissociated a certain amount of copper ions under certain p H conditions. Copper ions can catalyze the decomposition of hydrogen peroxide into highly reactive hydroxyl radicals, which can destroy the pigment on the fabric effectively, and thus achieve the purpose of reducing the temperature and the p H value of the bleach solution.By the combination of cationic gelatin protein and metal protein complexes, the multifunctional auxiliary agent for bleaching and modification of cotton fabric was prepared. The best technology for the application of the additive in the modification of cotton fabric with hydrogen peroxide bleaching was optimized. Additive 5g/L, 30%H2O210m L/L, penetrating agent JFC 1g/L, scouring agent 0.2%(omf), bleaching 20 min at 70℃, and then 4 g/L sodium silicate and 3 g/L sodium hydrate were added, preserved for 40 min. The cotton fabric modified and bleached by this procedure not only obtain good whiteness, but also improves the dyeing property of reactive dyes for cotton fabrics, which can achieve the purpose of reducing the amount of salt and the dye.