Study of the Relationships between the Chemical Structures of Azo Disperse Dyes and their Dyeing Properties on Polyester

Abstract

A series of azo disperse dyes was synthesized using 4-nitro aniline and 2-chloro-4-nitro aniline as diazo components. The coupling components were N,N-diethyl aniline, N,N-bis-β-hydroxyethyl aniline, N,N-bis-β-acetoxyethyl aniline, N,N-diethyl-m-toluidine, N,N-bis-β-hydroxyethyl-m-toluidine and N,N-bis-β-acetoxyethyl-m-toluidine. The structures of the synthesized dyes were confirmed by TLC, 1H NMR and elemental analysis. The spectroscopic properties of the dyes when dissolved in the organic solvents viz. ethyl acetate and methyl benzoate, were investigated. The absorption spectra of the dyes showed a bathochromic shift when the polarity of the solvents increased. In addition, the substituent groups on the dye structures influenced the spectroscopic properties of the dyes. The dyeing properties of the dyes on poly(ethylene terephthalate) and poly(lactic acid) fabrics were also studied. The dyes exhibited a slight difference in shade on the two polyester fabrics. Heat and light fastness properties of the dyed fabrics were also examined.