Coloration of polyester fiber with natural dye henna (Lawsonia inermis L.) without using mordant: a new approach towards a cleaner production

Introduction Polyester is a general name given to the fibers usually made from polyethylene terephthalate having ester functional group in their main chain and formed through the polycondensation reaction of a glycol (or diol) with a difunctional carboxylic acid (or diacid) (Edlund and Albertsson 2003). The presence of two functional groups of each reacting species results in the formation of a linear polyester molecule. Polyesters are of great importance as fiber materials in terms of volume and product value due to their versatility in various application sectors with relatively low raw material and production costs (Park and Kim 2014). Among all the classes of polyester fiber, the most commercially Abstract