Alkaline extraction of natural dye from mugwort and its dyeing on silk fabric

Natural dye from mugwort was extracted with NaOH solution.This paper discussed influence factors on extraction results,such as NaOH concentration,extraction temperature,extraction time,solid to liquid,and discussed influence factors on dyeing results of silk fabrics,such as dyeing pH,dyeing temperature,dyeing time,Na2SO4 concentration,and dye dosage.It was found that the dyed silk fabrics with NaOH solution extracts from mugwort had better colour strength than the dyed silk fabrics with extracts obtained in water.The optimum conditions for the extraction were as follows: NaOH 0.3mol/L,extraction temperature 90?℃,extraction time 40min,solid to liquid 1∶35.The optimum conditions for the dyeing on silk fabrics were as follows: pH value 5.0,dyeing temperature 90?℃,dyeing time 60min,Na2SO4 50?g/L,bath ratio 50∶1.Furthermore,the dyed silk fabrics with alkaline extracts had moderate fastness properties and that mordanting did not result in any significant improvement in fastness properties.