Research On Synthesis And Application Of New Hydrogen Peroxide Bleaching Activator

Cotton fabric is loved by the majority consumers because of its good moistureand soft handing. Bleaching with hydrogen peroxide of cotton is conventionallyperformed under strong conditions such as high temperature and concentrated alkalinesolution, which may lead to large energy consumption, bad handing and sever fiberdamage. In order to reduce energy consumption and improve the quality of cottonfabric, the low-temperature hydrogen peroxide bleaching activators gradually get thefavor of home and abroad scholars in printing and dyeing industry as an importanttechnology of low-temperature hydrogen peroxide bleaching recently.In this study, we synthesized a type of low-temperature hydrogen peroxidebleaching activators including cyanide with epichlorohydrin and dicyandiamide in thecatalyst role of boron trifluoride ether. The synthesized products were characterizedby modern testing techniques, such as Fourier transform infrared spectroscopy andmass spectrometry, and the synthesis process was optimized by evaluating theproduct yield; to explore the feasibility of synthesized products applications in lowtemperature hydrogen peroxide bleaching of cotton fabric, the temperature stabilityand alkali stability of synthesized products were investigated; the influence factors ofhydrogen peroxide decomposition by low-temperature hydrogen peroxide bleachingactivation system and decomposition kinetics of the hydrogen peroxide were alsostudied; based on the theoretical research, the application process of low temperaturehydrogen peroxide bleaching activators in cotton fabric was optimized by testing thefabric CIE whiteness index and other fabric properties, the conclusions are asfollows:(1) The unsaturated bond of carbon and nitrogen of cyano hydrogen peroxidebleaching activators were characterized on the infrared spectra by appearingabsorption peak on2191cm-1and2160cm-1; the relative molecular weight of theproducts measured by mass spectrum was176,which was an even number, indicating that the product contained an even number of nitrogen atoms according to the rules ofnitrogen and also the relative abundance of mass to charge ratio m/z=179was onethird of mass to charge ratio m/z=177, indicating that the measured moleculecontained some chlorine atoms, which was consistent with the product formulaC5H9N4OCl, meaning that the target product was made.(2) According to the product yield, the optimum synthesis process was as follows: theproduct yield can reach80%when reacted for6h under the condition that the molarratio of epichlorohydrin and dicyandiamide was n (ECH): n (DICY)=1.25:1, themolar percentage of a boron trifluoride diethyl ether was16%, the solvent volumewas100ml when the molar of epichlorohydrin n (ECH) was0.2mol, the reactiontemperature was60℃.(3) The new hydrogen peroxide bleaching activators has good temperature stabilityand alkali resistance stability, which has a good coherency with the conditions ofcotton fabric bleaching. The rate of hydrogen peroxide decomposition activated bynew hydrogen peroxide activation system was affected by factors such as activatordosage, pH value and temperature. In order to ensure the effective decomposition ofhydrogen peroxide and make the activation system of hydrogen peroxide have a lowerinitial hydrogen peroxide decomposition rate and higher equilibrium hydrogenperoxide decomposition rate, the factors of activation system must be strictlycontrolled; the hydrogen peroxide decomposition rate of activation system reached to90%when exposed to4g/L activator dosage, pH value11, on70℃for60min,which showed a good low temperature activation; and the activation systemdecomposing hydrogen peroxide hydrolysis kinetics obeyed pseudo-first-orderequation, which provided theoretical reference for its application on fabric bleaching.(4) The optimized process of new hydrogen peroxide activation system bleachingcotton fabrics was as follows: the dosage of30%hydrogen peroxide was20g/L,hydrogen peroxide bleaching activator dosage was4.0g/L, sodium hydroxide dosagewas2.0g/L, scouring agent F dosage was2.0g/L, stabilizer S dosage was1.0g/L,fabric treated on70℃for60min. The whiteness index of new type hydrogenperoxide activation system bleaching process was higher than TAED activation bleaching process; though the cotton fabric whiteness index of new hydrogenperoxide bleaching activators process lower than the traditional bleaching process,still the fabric strength loss of new type hydrogen peroxide bleaching activatorsprocess was reduced by almost half compared with traditional bleaching process,which showed a large space for development of new type hydrogen peroxideactivation bleaching system.