Tea polyphenols as an indigenous natural plant resource in preparation of azo dyes for dyeing textiles

Abstract

For thousands of years. until as recently as the discovery ofthe first synthetic dye in 1RS6. all colouring substances were of natural (vegetable. animal, lichen and mineral) origin. After the discovery of first synthetic dye, there was a gradual decrease in the use of natural dyes. which were more expensive and in many ways more difficult to use. Today. many of the natural dyes have been replaced by synthetic dyes. The major problem threatening the textile industry today is the environmental pollution, arising out of the wet processing of the textiles. The production of synthetic dyes involves many violent reactions. using. manv hazardous petroleum based primary chemicals as well as the production of hazardous intermediates. Therefore it is high time that the over utilization of synthetic dyestuffs should be thought about in the context of health of the people and environment. Natural dvcs extracted or developed from natural resources exhibit better biodegradability. higher compatibility with the environment and also a lower toxicity and allergic reactions not to mention the unique and fascinating colours.