SYNTHESIS OF ECO-FRIENDLY DYES

Abstract

This research project had three aspects, 1. Synthesis of novel dyes, 2. Assessing their applications i.e. fastness properties etc. 3. Testing the synthesised dyes for their mutagenicity. Synthesis and evaluation of azo disperse dyes was done while using different aminoflavones (4 ́-Aminoflavone, 3 ́-Aminoflavone and 6- Aminoflavone), and coumarins (like 6-Amino-4-methylcoumarin and 4-Methyl- 7-hydroxy-coumarin). Dyes (16-75) have been synthesized by coupling the synthesized intermediates with the substituted aniline (1-10) as well as the naphthalene based couplers (11-15). The characterization of the dyes was done by Infrared, 1H-NMR, Mass Spectrometry, 13 C-NMR and Elemental analysis. Diazotization of the different heterocyclic amines (1a-10a).was carried out and the 4-Methyl-7-hydroxycoumarin was used as coupler to yield the dyes (76- 85). The synthesised dyes were applied on the polyester fabric and it proved to be effective as they gave good fastness properties. The dyes obtained had good fast colours ranging from orange to purple. Some of the synthesised dyes (16, 17, 20, 23, 24, 28) were also applied on the Nylon-lycra fabric and it gave good dyeing as well as good to moderate fastness properties. The yield of the dyes obtained was from 65-83 %. All the synthesised dyes were evaluated for their mutagenicity by undergoing standard Ames test. This was performed by using the Salmonella strains (TA 98 and TA 100) with and without S9 activation. The results of these mutagenicity results showed that almost all the dyes proved to be negative in the Ames test except the dyes having free amino group which can be attributed to be cause of their mutagenicity. The presence of the free amino group made these dyes more prone to be mutagenic as compared to the other dyes.