Synthesis and Application of Disperse Dyes Derived from 2-Aminothiophene Using Acetoacetanilide as the 1, 3-Dicarbonyl Compound

Abstract

Disperse dyes derived from 2-aminothiophene diazo components was synthesized using via Gewald reaction, the intermediate were diazotized, coupled and the dyes were purified by re-crystallization. The melting points were found to span from 163°C- 209°C and spectroscopic assessment such asFT-IR spectroscopy and GC-MS were carried out to elucidate their structures. The vibrational frequency obtained for the synthesized dyes shows the characteristics absorption peaks due to stretching frequency of the NH-group in the region 3097-3365cm -1 . An absorption peak in the region 2217.8, 2221.5, 2214.0, 2206.6cm -1 was observed for dye A, A1, B and B1 due to the presence of cyano group. The IR spectra of the prepared azo dye also showed an absorption peak in the region 1438.8-1599cm -1 ascribed to V N=N, while the observed vibrational frequency in the region 1602.8-1736.9 was due to V C=O .The disperse dye A, A1, B and B1 were applied at 2% depth on polyester and nylon 6,6 fabric and gave purple, deep purple and deep pink hues with brighter and deeper shades, tinctorial strength and excellent levelness on the fabric. All the dyes show good to excellent fastness to washing on polyester fabric and fair to very good fastness to washing on nylon 6,6 fabric respectively. The remarkable degree of levelness and brightness after washing indicate good penetration and excellent affinity of the dyes to the fabric. However, dye C and dye C1 gave yellowish to deep yellowish hues with excellent tinctorial strength and brightness on the nylon 6,6 fabric. However, the light fastness ratings of the dyed polyester and nylon 6,6 fabric shows moderate to very good light fastness.