Abstract:
The synthesis of direct dyes derived from terephthalic and isophthalic acid using J and H- acids was
undertaken with the view of replacing benzidine moiety in the production of direct dyes. The amide derivatives
of isophthalic and terephthalic acids were used as the coupling components while aniline and its derivatives
were used as the source of diazo components. The amide derivatives were characterized by Gas
Chromatography/Mass Spectrometry and Infra-red analysis. The spectroscopic properties of the dyes in various
solvents were also examined and most of the dyes showed bathochromic shifts when the solvent was changed to
more polar solvents. The dyes also showed positive and negative halochromism with the addition of few drops of
hydrochloric acid (HCl). The synthesized dyes were applied to cotton fabrics and their performance properties
evaluated. They have good exhaustion in the presence of electrolyte and have good wash fastness properties
upon application of after-treating agents of values of 3-4, 4 and 4-5. They also had good fastness properties to
light of values between 4-7. Their resistance to rubbing and perspiration had values between 3 and 4-5. The
toxicity of the synthesized coupling components was studied using the Dietrich Lorke (LD50) method on Albino
miceand they were found to be non-toxic.
