ABSTRACT Due to the difference in chemical compositions and dye absorbency between cotton and modal fibers, it is very difficult to achieve uniform unit dyeing of cotton–modal blend fabrics. Normally, Reactive dyes, which are widely used for dyeing cellulose, often require high amounts of salt, alkali dosages, and other auxiliaries to gain even dye uptake. These conditions cause nonuniform shade development, high effluent load, poor wash fastness, and also impact the environment badly. In this study, for the investigation of chitosan, a natural bio‐polymer derived from chitin, as a bio‐catatonic modifier is used instead of synthetic modifier to improve the dye ability of cotton–modal blends fabrics. Chitosan premises amino functional groups that donate positive charges to the fiber surface, improving dye‐fiber affinity with anionic reactive dyes. This modification with chitosan lowers salt and alkali consumption, improves color yield ( K / S ), develops fixation, and promotes level even shades across cotton and modal fibers. The results revealed that chitosan treatment notably improved dye uptake, fixation % uniformity, and overall fastness properties, while contributing to environmental sustainability by lowering chemical load in effluent discharge, maintaining the pH, COD, and BOD. This approach offers a stable pathway toward eco‐friendly and efficient dyeing of blended fabrics.
Sharif et al. (Wed,) studied this question.