Dyeability of cellulose fibers using dyestuff from African rosewood (Pterocarpus erinaceous)

Methanol extracted from the “heart wood” of the plant Pterocarpus erinaceous (African rosewood) gave a brick red dyestuff. Chromatographic separation of the dye produced a single homogenous component with an Rf value of 0.78, a yield of about 17.3% and a melting point of 86°C. IR spectrum of the purified dye showed the presence of an aromatic CC double bond band at 1620–1470 cm−1 and NH2 absorption characteristic of an aromatic amine NH stretch at 3590–3400 cm−1, while para-disubstitution on aromatic nucleus was observed at 850–840 cm−1. A wavelength of maximum absorbance, λmax, of 500 nm was recorded on a UV/visible scan for the solvent soluble dye. The dye, which was substantive to cotton, was applied quantitatively to it and reed fibers by exhaust dyeing technique from locally distilled alcohol.