Extraction of dyestuff from the Alliumcepa L. and its application in the dyeing of wool

ABSTRACTThe natural dying is made by taking advantage of the pigments available in the nature.Various mordants are used in order to bind a number of natural dyes to the fibers. The naturalpigment anthocyanin produced from the Alliumcepa L. skin is available in a number of fruitsand vegetables. As a result of an antioxidant and pharmacological characteristic of thissubstance as well its ligand feature, and because of giving color complex with various metals,it is used as a corrosion-preventing material in the industry.In this study, natural pigment anthocyanin produced from the Alliumcepa l. skin, by the use ofvarious transition salts as mordant substance, a wool fabric dying was carried out according tothe pre, joint and final mordanting methods by using tampon solutions at the pH=2-8 intervaland at 980C. Additionally, another work is carried out by the use of tannic acid together withvarious transition metals used as a mordant. It has been determined that when tannic acid isuse in wool dying in order to remove the little worms and allergen substances, it has beenseen that a better light and washing fasting with anti-bacterial and antiviral characteristics.The tannic acid, as a result of its characteristic, is planned to be used in our work. The woolfabric samples are dyed up for a period of 1 hour at 980C at pH values of 2, 4, 6, 8 with theseparate methods developed accordingly. Additionally, various studies are carried out on theeffect of mordant and mordant salt in dying.The anthocyanin that is dissolved in water and mostly used for food dye is tied up to the fiberand according to different methods of dying by using various mordant substances in order toprevent its dissolution in the water, appropriate pH and appropriate mordant and convenientdying methods are determined at environments with or without tannic acid by using tamponsolutions at 980C and at pH=2-8.Key words :Alliumcepa L., anthocyanin, tannic acid, mordant, wool fabrics.