Chemical modification of linen fabrics for salt free dyeing with anionic dyes

Abstract

As is known, in order to reduce the ionic repulsion forces between cellulosic fibers having anionic charge in the dyebath and anionic dyestuffs (direct, reactive, etc.) used in dyeing, it is necessary to add a considerable amount of salt to the dyebath particularly during reactive dyeing. The high salinity in the wastewater is an environmental hazard. For this reason, in this study linen fabrics were subjected to cationization process in order to achieve salt free dyeing with direct and reactive dyes. In order to determine the optimum conditions of cationization process, linen fabrics were treated with polyaminochlorohydrin quaternary ammonium based cationization agent at different concentrations, pH values, times and temperatures. Then the cationized fabrics were dyed with direct and reactive dyes. Nitrogen content (N%), Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) analyses were also realized to investigate the effects of cationization process on chemical and morphological structure of flax fibers. According to the experimental results, the optimum conditions for cationization of linen fabrics were found to be 9% cationization agent, pH 10 and 75 degrees C for 45 minutes. Furthermore, it was determined that the color efficiency was higher in case of cationized and salt free dyed linen fabrics compared to the un-treated and conventionally dyed samples.