Facile synthesis and properties of alkali-clearable azo disperse dye containing a carboxylic ester moiety

A yellow, alkali-clearable azo disperse dye containing a carboxylic ester moiety was readily synthesized from the reactant p-aminobenzoic acid by successive diazotization, coupling reaction, chlorination and esterification with ethanol. Then its molecular structure was characterized by FTIR. H-1 NMR, C-13 NMR, mass spectrometry and elemental analysis. The synthesized dye and a similar control dye containing the acylamide moiety (I) were applied to dyeing poly(ethylene terephthalate) fabric and their washing and rubbing fastness properties with different post-treatment methods (reduction clearing and alkali clearing) were examined and compared. It is found that the ester-containing disperse dye shows good alkali-clear ability on poly(ethylene terephthalate) fabric and contaminates little to environment due to the absence of reductants, as well as low toxicity and easy recycling of the hydrolysates. (C) 2014 Zhi-Hua Cui. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.