A novel approach for a natural dyeing process of cotton fabric with Hibiscus mutabilis (Gulzuba): process development and optimization using statistical analysis

Since early times, dyes derived from natural sources have emerged as an important alternative to synthetic dyes. Therefore, there is a need to develop new techniques of leaching natural colorants from plant materials for dyeing applications. esent paper investigates an eco-friendly dyeing process of cotton with the aqueous extract of Hibiscus mutabilis (Gulzuba) without metal salts. During this process, the dyeing step was carried out on modified cotton by several cationizing agents in order to improve its dyeability. Cationized cotton fibres were characterized by Fourier transform infrared (FTIR) spectra and the scanning electron microscope (SEM) images. The effect of the main operating conditions (pH of the dye bath, temperature, dyeing duration, cationizing agent nature and concentration) on the dyeing quality resulted has been studied. Then, the optimization of the dyeing process was released using a response surface methodology. rformances of this dyeing process were evaluated by measuring the colour yield (K/S) of the modified cotton. It was found that cationizing cotton improves the dyeing quality and the fastness properties.