Ecofriendly synthesis and application of special disperse reactive dyes in waterless coloration of wool with supercritical carbon dioxide

The coloration textile in supercritical carbon dioxide with water free has become more and more important and meaningful recently due to its Ecofriendly and environmentally friendly advantages. However, the lacks of special dyes for this waterless coloration technology are limiting its application in industry; especially for the shortage of disperse reactive dyes for natural fibers. Therefore, in this work, three special disperse reactive dyes involving diazo parent structures and reactive groups of dichlorotriazine were successfully synthesized and then applied at the first time for waterless coloration of wool fabric with supercritical carbon dioxide. Moreover, a safer and Ecofriendly method was developed for synthesis of the disperse reactive dyes by diazotizing of the alkalescent arylamine of 2-chloro-4-nitroaniline in the presence of a safer and milder acid of hydrochloric acid rather than concentrated sulfuric acid, in an environmentally friendly media of polyethylene glycol 200 mixed with water. The obtained dyes were successfully characterized and confirmed from chemical structure and color characteristics by Fourier transform infrared spectra, nuclear magnetic resonance hydrogen spectroscopy, liquid chromatography-mass spectrometry and ultraviolet-visible absorption spectroscopy. Furthermore, the application results reveal that good coloration behaviors and characteristics, commercially satisfactory leveling property and color fastness were achieved with the synthesized disperse reactive dyes on wool fabric in supercritical carbon dioxide media. All results indicate that the supposed method is essentially useful for developing special disperse reactive dyes with safe and Ecofriendly characteristics, and the obtained disperse reactive dyes are potentially hopeful for waterless coloration of wool with supercritical carbon dioxide media instead of conventional wet-chemical processes for cleaner production in wool industry. (C) 2016 Elsevier Ltd. All rights reserved.