Modification of cotton fabric with cationic reactive compounds in bleaching to improve reactive dyeability

Abstract

The reactive dyeability modifying agent of cotton fabric, 3-amino-2-hydroxyl-propyltrimethylammonium (3,5) dichlorotriazine, was prepared. Spectroscopic technique ('H NMR) was employed to characterize the chemical structure of the modifying agent. After that, the modifying agent was applied onto scoured cotton during bleaching process, aiming at modifying dyeability of the fiber using single-bath. The nitrogen content of modified cotton fabric was analysed by an elemental analyzer and whiteness was also evaluated. The results showed that nitrogen content in modified cotton fabric increased with an increase in the amount of the modifying agent concentration whereas whiteness index slightly decreased. Based on the finding results, it was possible that the dyeability modification and bleaching could be carried out in single bath process with a slight decrease in the performance of hydrogen peroxide. The dye uptake and color strength of dyed modified fabric were markedly increased with an increase in the concentration of the modifying agent. In addition, those properties obtained from modified cotton fabric were higher than that obtained from the dyeing from unmodified cotton fabric. This was attributed to the presence of the cationic groups of the modifying agent that played a crucial role in attracting the anionic dyes from the dye-bath. The finding results tended to suggest that the dyeing properties of modified fabric were exactly dependent on the efficiency of the modifying agent fixation on cellulose during concurrent modifying and bleaching of cotton.