Synthesis And Application Of Red And Blue Dyes For Synthetic Fibers

As the most important textile fiber, synthetic fiber whose yield is 50.3% of the total fibre yield in the world contributes greatly to the textile industry and social economic development. As special dye for synthetic fibers, such as acetate fiber and polyester fiber, disperse dye has high demand in the textile market, with azo disperse dye and anthraquinone disperse dye as the most popular ones. Azo disperse dye is valuable for its outstanding coloring intensity and easy manufacturing process, while anthraquinone disperse dye boasts for high light fastness and excellent dyeing effects. At present, study on dyeing of some novel hydrophobic synthetic fibers, such as polylactic acid fiber, supermicro polypropylene fiber, etc, becomes focus, since traditional disperse dyes cannot get satisfactory dyeing effect on such fibers while there are lack of novel dyes synthesized according to the special characteristics of such fibers. Moreover, study on structure-activity relationship is quite insufficient.A series of 6-acetamido-4-hydroxy-3-(phenyldiazenyl)naphthalene-2- sulfanilamide was synthesized with linear alkyl groups which may increase the affinity between dyes and synthetic fiber as PLA and PP. The affinity could be adjusted by changing the length of alkyl groups in order for dyeing different fibers. By diazotization-coupling reaction, amido protecting reaction, chlorosulfonylation, and sulfonamination reaction, such dyes were synthesized and applied on the dyeing of PLA, PP and PET. Under optimal conditions, dyeing exhaustions, K/S and fastness were achieved, which showed that affinties could be adjusted by changing the length of alkyl groups: For PLA and PP, C₈ got the best effect while for PET, C₄ was the best one.For study on structure-activity relationship, 7 1,4-disubstituted anthraquinone dyes with linear alkyl groups or aryl groups were selected on the dyeing of PLA, PP and PET. The study showed that: For PLA and PP, anthraquinone dyes with linear alkyl groups got better effects, while for PET, anthraquinone dyes with aryl groups were better. Such results were coincident with similarity and mutual attraction theory.