Abstract

• In this research work, the bark of Acacia auriculiformis A.cunn (malay-sha-padauk) was collected from Pyay Township, Bago Region. Physicochemical parameters of the raw bark powder such as moisture content, ash content, bulk density and pH content were determined. Natural dyes were extracted from the bark of malay-sha-padauk by different solvents (water, ethanol and methanol). The prepared natural dyes were characterized by FT IR, EDXRF and UV-Visible analyses. Relative abundances of elements in the extracted dye were analyzed by EDXRF which showed the chemical constituents of the element. The phytochemical tests of extracted natural dye were carried out. Furthermore, the antimicrobial activities of malay-sha-padauk dye were investigated by Agar Disc Diffusion method on six tested organisms. The maximum wavelength (λmax) of dyes extracted with water, ethanol and methanol were 490 nm, 489 nm and 497 nm, respectively. Sorption properties of 1000 ppm natural dye solutions dyeing on cotton were studied at different temperatures (40, 50, 60, 70 and 80 °C) and contact time and pH (3, 4, 5, 6, 7 and 8) by UVVisible spectrophotometer at different wavelengths for the various extract of malay-sha-padauk bark. From the experiment, it was revealed that the optimum temperature of dyes were at 70 °C and the optimum condition of dyeing on cotton were contact time of 50 min and pH 6. At optimum conditions, natural dye solutions with different alum dosages dyeing on cotton were studied by using UV-Visible spectrophotometer and more effective mordant (alum) dosage of 0.1 g was achieved for the dyeing process. The dye sample solutions were prepared by mixing natural dye powder with alum, onion peel, jengkol peel and tea waste to improve colour strength of dyes. Natural dye solutions dyeing on cotton were studied under optimum conditions by using three mordanting methods (pre-mordanting, simultaneously mordanting and post-mordanting).The colour intensities of these dyeing cotton was determined by Reflection Transmission Color Densitometer.