Synthesis and Characterisation of Colorants Derived from 1,4-Diamino Anthraquinone Polyamides

In this study, the polycondensation products of a diamine anthraquinone (1,4-diamino anthraquinone) and some aliphatic diacids with different methylene numbers were synthesised. Their UV-visible spectroscopy and thermal properties were then characterised. The synthesis was achieved by reacting equimolar solutions of the amine and the acid halides. The structure and thermal properties of the products were characterised. FT-IR Spectra of all the three products revealed the formation of amide due to the presence of strong bands at 1565 and 3390 cm −1 assignable to C=O stretching and N-H vibrations. Differential Scanning Calorimetry revealed high melting exotherms for the products. Thermogravimetry revealed moderate thermal stabilities for Poly NAM and Poly NAS and low thermal stability for Poly NAA which indicated 5.9%, 7.1% and 61.2% weight losses at 285˚C, 285˚C and 374˚C for the three products respectively. The wavelengths of maximum absorbance for the dye samples are 601.5, 591 and 589 nm respectively with absorptivity coefficients ( ) of 11640000, 11610000 and 11560000 respectively. 1% 1cm a