Studies On Application Of Dyes With Long Carbon Chain On Synthetic Fibers

Polypropylene (PP) fibers have risen to the 4th important synthetic fibers in the world, especially when fine PP fibers came out, their application in clothing industry has been improved. But problems all along exist in dyeing of PP fibers, so their wide application is greatly restrained.The dyeability of PP fibers can be enhanced to some extent by dope dyeing and modification of PP fibers, but the problems in dyeing have not been solved radically. Therefore the research on synthesis of special dyes and application of novel dyeing technology of unmodified PP fibers make great sense.In this research work, unmodified PP fibers were dyed with dyes with long carbon chain to get sufficient color strength and satisfactory fastness. Meanwhile dyeing polyester (PET) fibers with these special dyes was also attempted to improve the sublimation fastness of the dyes on PET.On the basis of the dyeing process for PET fibers, dyeing of PP fibers at high temperature and high pressure, and by after-treatment with heat were studied in consideration of nonpolar and undyeable structure of PP fibers. The methods, such as dyeing in solvent, with emulsified dye liquor and by triturated dyes in liquor were all attempted, and the optimized conditions were achieved.The effects of dyeing process and swelling degree of PP fibers on dyeing behaviors were investigated. Some optimized process conditions and parameters, such as temperature, time, pH value and amount of auxiliary added were obtained via a series of single factor tests. And the relationship between dye structures and dyeing behaviors was emphatically investigated. Sufficient color strength was achieved for PP fibers with azo dyes, and K/S could reach 17.03. K/S of PP fibers dyed with 1-alkylaminoanthraquinone dyes got to 9.5.PET fibers were dyed with the dyes with long carbon chain and the dyeing properties were studied. Sufficient color strength of the fibers was also gained. The sublimation fastness of the dyes was increased by 2-3 grades compared to that of C.I. Disperse Yellow 16 on PET fibers, and other fastnesses were all improved. The satisfactory dyeing results offer a way to resolve the problem of low sublimation fastness of disperse dyes on PET.