Synthesis and Dyeing Properties of Novel Bifunctional Reactive Dyes Via 4-(4-Methoxyphenyl)-Thiazol-2-Amine and 4-(4-Bromophenyl) - 1, 3- Thiazol- 2- Amine on Nylon Fabric

Bifunctional reactive dyes are coloured compounds that posses more than one reactive moiety per molecule or groups, capable of forming covalent bonds between dye ions or molecules and the substrate. Two bifunctional reactive dyes 10c and 10d with a single monochlorotriazinyl and vinyl sulphone reactive groups were synthesised via (4-methoxyphenyl)-1,3-thiazol-2-amine and 4-(4-bromophenyl)-1,3- thiazol-2-amine. These intermediates were diazotized and coupled with J-acid and other coupling components to derive the dyes. Wavelength of maximum absorption (?max ) of dyes were obtained. Dyes were applied on nylon fibres at various pH and temperature conditions. Optimum % exhaustion, % fixation and fixation efficiency were determined in glubber salt as the fixing agent. Washing and light fastness properties of dye samples were determined. The results revealed a ?max of 500nm(10c) and 480nm(10d) respectively, % exhaustion values of 69 and 67 at pH 11, 73% and 69% at 80oC in 70 minutes respectively, % fixation gave values of 69 and 65 at pH 11 respectively. The fixation efficiency values of 61% and 68% at pH of 11 respectively. The fairly good shades observed may be due to better, substantivity as well as good covalent fixation of the dyes with nylon fabrics. The colour strength and fastness properties of dyed fabrics were fairly comparable to that of cotton fabrics. The overall results suggest that bromo and methoxy groups introduced on the para position of benzene ring of dye molecules induced a hypsochromic shift of 10nm on 10c and 30n on 10d with respect to 10a.