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 NMR, C 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. 2014 Zhi-Hua Cui. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.