ESSTEBIO APSARA YELLOW

详情

RHEUM EMIDO is one such natural colorant found in the sub-alpine and alpine Himalayas at an altitude of *******0 meters. Rheum emodi is a medicinal herb and belongs to the family Polygonaceae. The Indian rhubarb (Rheum emodi) commonly known as Dolu (Sanskrit: Amlaparni, Revatchini) are reported to be used for curing of a variety of diseases, its main effect being a positive and balancing effect upon the whole digestive system. The rhizomes and roots of Rheum emodi yield a yellow coloring matter, which could be used for textile coloration. The plant contains *5% anthracene derivatives. In the plant the anthraquinoid components are present in reduced form as anthraglycosides, which hydrolyze and oxidize to the respective anthraquinone. The extracted dye contains a complex mixture of anthraquinones; relevant compounds are Emodin, Chrysophanol, Aloeemodin, Rhein, and Physcion and the chief colouring component is chrysophanic acid. The formation of complexes due to the presence of metal salt from mordanting considerably improves dye uptake and all round fastness properties. Mordant brings about change of the hue of the natural colorants, which can be utilized with advantage to produce different shades on protein and cellulosic substrates. Keeping environment related issues and adoption of cleaner technology in view, inorganic salts such as, aluminium sulphate, potash alum, and ferrous sulphate can be employed as mordanting agent in view of their good complex forming ability and environmental safe character.