Novel Dyeing Method for Polypropylene Fiber via Reduction and Oxidation Processes of Cationic Dye

Polypropylene (PP) fibers have various excellent characteristics. However, it is difficult to use PP fibers for fashionable apparels due to its poor dyeing properties. Hence, in this paper, it has studied that developing a novel simple and inexpensive dyeing method for PP fibers by utilizing a cationic dye. It was developed that the PP dyeing method with the reduced form of a cationic dye, namely, leuco form. In the method, the permeability and affinity of the cationic dye for PP fibers would have been enhanced by reducing the cationic dye treated with a reducing agent in the alkaline aqueous solution. As a result, the reduced form of the cationic dye was adsorbed onto the PP fibers. Although, the color of the dye disappeared under an alkaline condition, the adsorbed cationic dye was recolored and fixed by treating with an oxidizing agent, and the dyed PP fibers were obtained. Following aforesaid method, the dyed PP fabrics were obtained by reducing the cationic dye with glucose under an alkaline condition at 100 ̊C and oxidizing it in an aqueous acetic acid solution at 50 ̊C. It was found that the L* of the dyed fabrics were low when Basic Blue 3, Basic Red 2, Basic Yellow 7, and Basic Orange 14 were used as a cationic dye.