Cardanol-Based Bis(azo) Dyes as a Gasoline 91 Colorant

Novel bis(azo) dyes were successfully prepared from the coupling of either natural cardanol or its hydrogenated derivative with a series of diazotized aromatic amines and diamines. These new dyes were fully characterized by NMR, infrared and UV-visible spectroscopy and mass spectrometry. The dyes are highly soluble in a variety of common organic solvents and gasoline as a consequence of the cardanol unit. The physical properties of gasoline according to American Society for Testing and Materials standard were unaffected by the presence of the bis( azo) dye derived from 1-(4aminophenylazo)-2-naphthol at a concentration of 6 ppm and the dye showed excellent stability over a 3 month period.