Chemical Modification Of Turmeric & The Properties Of The Modified Dyestuff

The structures of the natural dyes were summed up and analyzed. And we recount the pros and cons of the natural dyes. We put forward a new idea in order to conquer their inherent disadvantages, which is modifying natural dyes with chemical method.We select CI Natural Yellow 3:Turmeric as a coupling component, and choose p-Aminobenzenesulfonic acid as a diazo component, then combine the diazonium salt with Turmeric introducing sulphonic acid group in it. We obtain a soluble modified dyestuff.We study the properties of the modified dyestuff. Our tests show that the wash fastness of the dyed silk samples is 4-5, and its light fastness is 2. On the same condition, the wash fastness of the silk samples dyed with Turmeric is 2, and its light fastness is 1, the silk samples almost become white. The light fastness of the modified dyes is still low, but its practical values are much better than Turmeric.