Ultrasound-assisted extraction of natural dye from Swietenia mahagoni and its application on silk fabric

Abstract

The current study deals with the extraction of natural dyes from the flower of the Sweitenia mahagoni plant by ultrasound-assisted extraction method using ethanol as solvent. Box-Behnken design has been employed to optimize and investigate the effect of three independent variables (sample-solvent ratio, sonication time and extraction temperature) on the natural dye yield. The results reveal that the experimental data are fitted to a second-order polynomial equation using multiple regression analysis with high coefficient of determination value (R²> 0.98, Adj. R² >0.96 & Pred. R² >0.81). Optimal extraction conditions for the dyes yield are: sample-solvent ratio 1/20 g/mL, sonication time 30 min and extraction temperature 50°C. Under these conditions, the highest dyes yield is predicted to be 0.855%. FTIR spectroscopy has been used to identify the major chemical group in the extracted dye. Further, dyeing of silk fabric has been carried out by an exhausted dyeing method and the dyeing property and fastness properties of the dyed samples are also assessed.