Evaluation of the dyeing and fastness properties of wool fabrics treated by chitosan in different molecular weights and dyed with mint

Abstract

Chitosan solutions were prepared by dissolving chitosan polymers, which were provided in three different molecular weight as low, medium and high, in acetic acid solution and were applied to wool fabrics. After chitosan treatment, the half of the samples were dyed with dried mint by mordanting with potassiumaluminumsulphate and another half of the samples were dyed with dried mint without mordanting. In addition, mordanted and unmordanted dyeing processes were also applied to the samples that were not treated by chitosan for comparison. Following the dyeing processes, the color values of the samples were measured via spectrophotometer by selecting the wool sample dyed with mint only as a reference. Then, the samples were exposed to washing, rubbing and light fastness tests and evaluated. Moreover, the color values of the samples after washing were measured again in order to determine the effect of washing process to color yield. From the results, it was observed that wool samples dyed with mint were in yellow and green colors and chitosan treatment had positive effects on color yield. Mordanting process caused for the wool samples to be in yellower color shades and to significant changes in color yield. Washing process decreased the color yield in all samples. Rubbing and light fastness values were found to be in acceptable limits for natural dyeing. On the other hand, chitosan treatment in different molecular weights was not found to be significant but generally medium molecular weight chitosan resulted in the most available one.