Dyeing of Modified Polypropylene—Cationic Dyes on Brominated Polypropylene

Abstract

Polypropylene fiber was photobrominated by the action of bromine under specific conditions. With bromination, the moisture content of the fiber increased, but there was no effect on the fiber's mechanical properties and a marked affinity was created in the fiber for cationic dyes from an alkaline medium. Eight different cationic dyes were used on the brominated product under different dyebath pH conditions. Dyeings tended to show that the mechanism of application of cationic dyes on brominated polypropylene was a reactive type, i.e., through the formation of a covalent bond between the fiber and the dye. Of the eight cationic dyes, seven possessed poor to moderate lightfastness; only Methylene Blue (CI Basic Blue 9) gave very good lightfastness. In all the eight dyeings, fastness to washing, bleach, sea water, and soda boil were good. All the eight dyeings were aftertreated with iodine which increased lightfastness. Of the eight dyes, three produced photodegrading action on the fiber and five afforded photoprotection. Meth ylene Blue gave very good photoprotective action to the brominated polypropyl ene fiber.