Effect of metal ion binding of chitosan on the printability of pretreated wool fabric

In this study, chitosan was used as a pretreatment agent for wool fabric to increase the metal binding during the mordanting process with copper sulphate. The copper(II) binding was measured by measuring volumetrically the concentration of metal ions that remained in the solution after mordanting. The pretreated mordanted wool samples were then subjected to printing with a natural dye, 2-hydroxy-1,4-naphthoquinone (lawsone). The results indicate that color strength and wash fastness of the pretreated printed wool samples were enhanced compared to the untreated samples. This enhancement depends mainly on the molecular weight and concentration of chitosan.