Chitosan-cyanuric chloride hybrid as an efficient novel bio-mordant for improvement of cochineal natural dye absorption on wool yarns

Abstract

This study presents an ecological and economical method for dyeing and durable antibacterial finishing of wool with cochineal natural dye. Wool yarn was treated with prepared chitosan-cyanuric chloride hybrid (Ch-Cy), was checked for its capability to covalently react with wool, and its dyeing, color fastness, as well as antibacterial properties were also investigated. The influences of key factors such as Ch-Cy concentration, dye concentration, pH, time, and temperature of dyeing were investigated and optimized. Results showed that Ch-Cy (15% on weight of fiber ) treatment of wool had several beneficial effects which brought about remarkable improvement in dye uptake, decrease in optimum dyeing time and temperature, elimination of metal mordant from dyeing process due to bio-mordant role of Ch-Cy, and development of antibacterial finish against pathogenic gram negative Escherichia coli and gram positive Staphylococcus aureus bacteria which was durable up to 20 washing cycles. Color fastness properties of treated wool were all satisfactory and in acceptable range. It was concluded that the simple Ch-Cy treatment of wool can considerably assist to reduce energy consumption, chemicals, and dyeing costs which makes the process cost effective and eco-friendlier over conventional processes.