Relationship between Substituents of Aminoazobenzene Disperse Dyes and Dyeing Properties

Four aminoazobenzene disperse dyes derived from different N-ethyl-N-substitutedalkylanilines and 2-chloro-4-nitroaniline, were synthesized and their chemical structure were analyzed by 500 MHz NMR spectroscopy. The wavelength of maximum absorption of the synthesized dyes, which was dependent on the electron withdrawing ability of the substituent, was in the range of 499.5~526.0nm. As terminal substituent became polar, the dyeing rate of disperse dye increased, and the exhaustion rate of dyes having cyano or hydroxy group became lower, that of the dye having acetoxy group higher. The wash fastness of polyester fabric dyed with disperse dyes possessing the polar group improved probably due to the increased dye-fiber interaction.