Coloring efficacy of Nyctanthes Arbortristis based yellow natural dye for surface-modified wool

Abstract

Sustainable products particular plant pigments as colorants have gained a worldwide fame due to their ayurvedic and eco-friendly nature. In this research, improvement in colorfastness of Coral Jasmine ( Nyctanthes Arbortristis ) based yellow natural pigment has been investigated using eco-friendly shade developers (mordants) after being separated from crude mixture in aqueous medium and applied before and after dyeing of wool at given conditions in microwave radiation (MW). It has been found that 35 mL of yellow water extract (6 pH) of Coral Jasmine after irradiation upto 4 min, has given high colour yield onto MW-irradiated wool when used to dye wool at 85 °C for 35 min in presence of 2 g/100 mL of salt. Before dyeing 0.5% of tannic acid and 0.5 % of orange peel , 2 % of acacia and 1.5 % of pomegranate extract has developed colourfast shades of high strength. Similarly after dyeing, 2.5 % of tannic acid, 2 % of orange peel, 2.5 % of acacia and 1.5 % of pomegranate extract has developed colourfast shades of high strength also. It is inferred that eco-friendly mordants has played promising role in improving bio-colouring behaviour of wool with Nyctanthes Arbortristis but also addition of MW-rays to get high yield has made process more sustainable and valuable. • The microwave-assisted extraction of Nyctanthes dye was investigated. • Bio-mordanting were used as a replace of metal mordant. • Bio-dyeing of wool shown excellent fastness properties. • Nyctanthes Arbortristis based yellow natural dye can be an alternative of synthetic dyes.