New azo carboxylic dyes derived from eugenol: synthesis and preliminary application to polyamide

The growing demand for innovate routes to develop functional textiles initiated the necessity of new molecules. Azo dyes are the most important synthetic colorants which have been widely used in textile manufacturing.

From a chemical perspective, azo derivatives consist of aryl/alkyl and –N=N– groups, which are usually synthesized by diazotization of a primary aromatic amines and the coupling of the diazonium salts obtained with a generally activated aromatic substrates. The azo reactive dyes are generally characterized by having chemical groups capable of forming covalent bonds with the textile substrates, through a certain dye activation process.

Therefore, a series of azo dyes containing eugenol, the major phenolic compound in clove (Syzygium aromaticum) essential oil, were synthesized by coupling reactions of diazonium salts of different amines based on 3-aminobenzoic acid. The new eugenol-based azo dyes were full characterized by the usual analytical techniques and dyeing was then carried out on polyamide to determine its fastness and staining under washing conditions.