Insights into Cotton Dyeing Using Limoniastrum Monopetalum Leaves Aqueous Extract: Extraction and Dyeing Processes Optimization

A great deal of attention was addressed to the development of natural dyes that are safe, non-allergic, nontoxic, and environmentally friendly. In this investigation, Limoniastrum monopetalum leaves were studied as a source of ecological dye for cotton fabric dyeing. FT-IR spectroscopy indicated that the studied leaves were rich of hydroxyl and carbonyl groups suggesting the presence of phenolic and flavonoid structures. The extraction procedure was performed under different operating conditions; extraction time (5-90 min), temperature (30-120 degrees C), pH (2-11) and aqueous extract concentration (10-90 g/L). Response Surface Methodology (RSM), with the assistance of Minitab17.1.0, was used to estimate the interaction between experimental factors. The optimum conditions for the extraction procedure were; time = 15 min, temperature = 40 degrees C, pH = 9, and dye concentration = 80 g/L. Influences of the main dyeing conditions on the color strength (K/S) and the dye bath exhaustion [E (%)] were also discussed. The optimal values for dyeing were: pH of dyeing bath = 8.9, temperature = 100 degrees C and dyeing duration = 43 min. The fastness properties of colored cotton samples were found to be improved using alum, chitosan, and pomegranate peel as mordants.