Facile salt‐free process for cotton fabric dyeing: Pad‐irradiate‐pad‐steam process using 3‐chloro‐2‐hydroxypropyl trimethyl ammonium chloride

Abstract

AbstractSevere effluent pollution has set new requirements for eliminating the use of salts during the reactive dyeing of cotton. In this study, 3‐chloro‐2‐hydroxypropyltrimethylammonium chloride was used as an etherifying agent via a pad‐irradiate‐pad‐steam process with a reactive dye to cationize cotton. The fabric underwent a microwave‐assisted pad‐irradiate process, and the cationic fabric was dyed salt‐free using a reactive dye in a pad‐steam process. The influence of etherifying conditions on the nitrogen content, grafting efficiency of the cotton samples, and dyeing properties of cationic cotton fabrics were investigated. Cationic cotton samples have the same dyeability with a reactive dye without salt as with dyes used in a conventional pad‐dry‐pad‐steam process because of the increase in the electrostatic attraction between the dye and the cationic cotton. Such an approach that eliminates salts is beneficial to environmental protection. Properties of the dyed cotton (such as color evenness, washing, and rubbing fastness) obtained using the reactive dye made the cotton fabric wearable enough to satisfy standard requirements.