NOVEL HETEROCYCLIC DISPERSE DYES WITH THIOPHENE MOIETY FOR DYEING POLYESTER FIBRES

Abstract

Ethyl-2-amino-4-[(4-chlorophenyl)carbamoyl]-5-methylthiophene-3-carboxylate and ethyl-2-amino-4-[(2,4-dimethylphenyl)carbamoyl]-5-methylthiophene-3-carboxylate were synthesized by the reaction of sulphur, ethylcyanoacetate with 4-chloroacetoacetanilide and N-(2,4-dimethylphenyl)-3-oxobutyramide  respectively. The highly versatile aminothiophenes obtained were diazotized and coupled with various N-phenylmaleimides in the presence of fused sodium acetate, furnished a series of new monoazo disperse dyes. The dyeing performance of these dyes was assessed on polyester fabric by dyeing with the aid of a carrier and also under reduced pressure. These dyes were found to give yellow, deep pink, brown and brownish purple shades with very good levelness on the polyester fabric. Fastness properties of the dyed fabrics were measured and most of the dyed fabrics tested displayed very good wash, perspiration, sublimation and rub fastness ratings, however they had poor photostability. The fabrics dyed under pressure showed deeper hue of the colours even after washing.