Extraction,identification and sorption studies of dyes from madder on wool

Since the last decade, the application of natural dyes on textile materials is gaining popularity all over the world, possibly because of increasing awareness of environment, ecology, and pollution control. In this research, extraction of dyes from madder at different conditions has been studied. The extracted dyes from madder were examined by TLC and HPLC. The adsorption properties of the dyes extracted from madder on natural polyamide fibers (wool) were also determined. The rate of dyeing at different temperatures, as well as the values of standard affinity, entropy, and enthalpy was calculated. The results indicated that increase of temperature leads to decrease the values of partition ratio and affinity. The adsorption isotherm was tested by fitting the adsorption data with Langmuir, Freundlich, BET, and Temkin isotherms. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009