Researches on the Fixation Performance of Chitosan and its Derivative
The fixing performance of chitosan hydrochloride (CSH) with different molecular weight and chitosan biguanide hydrochloride (CSGH) as a fixing agent for cotton fabric dyed with reactive dyes was discussed. The results showed that the fixing effects of CSH on reactive dyes were related to its molecular weight, and the CSH with high molecular weight (HMW) exhibited better fixing effects than that with low molecular weight (LMW). The fixing effects of CSGH on reactive dyes were superior to that of the CSH with HMW, because of the CSGH molecule with positive charges and the imino groups, which could further strengthened the interaction among the CSGH, dyes and cellulose molecules. After treated by the CSGH, the soaping, perspiration and dry rubbing fastness of the dyed fabrics could be increased 0.5 to 1 grade, while the wet rubbing fastness of ones was also improved obviously. The infrared spectrum (FTIR) of the dyed fabric treated by CSGH showed that a cross-linking was formed among CSGH, dyes and cellulose molecules.