Solubility of Disperse and Mordant Dyes in Supercritical CO2

Abstract

Waterless dyeing is the new approach in textile dyeing in order to reduce or eliminate effluent waste, and supercritical carbon dioxide is an alternative solvent being considered. The research focus has therefore been on determination of dyestuff solubilities in supercritical carbon dioxide. We have determined the solubilities of two disperse dyes (C. I. Disperse Yellow 7, C. I. Disperse Oranges 11) and three mordant dyes (C. I. Mordant Brown, C. I. Mordant Yellow 12, and C. I. Mordant Red 11) at 323−343 K and pressures in the range 132−195 bar. Mordant Brown had the highest solubility in the range (1.2−5.1) × 10-4 mole fraction whereas Mordant Yellow 12 had the lowest solubility in the range (1.7−5.1) × 10-7 mole fraction. The disperse dyes and Mordant Red had solubilities of the order 10-6 mole fraction.