Synthesis And Application Of Sulfonamide-containing Dyes

The fibers and the dyes having similar structures always show high affinity between them. According to this theory, the hydrophobic sulfonamide dyes being composed of chromophore, sulfonamide group and different alkyl chains were designed and synthesized in this thesis. The dyes are tried to apply to PET, unmodified PP and PLA fabrics in expectation of high dye exhaustion and excellent color fastnesses.Two corresponding sulfonyl chloride intermediates are prepared in SOCl₂/DMF chlorination system by using two pyrazolone-containing acidic azo dyes as reactants. Then two series of yellow sulfonamide dyes are synthesized by the reaction of the sulfonyl chlorides and ammonia or different fatty amines in the presence of acid-binding reagent. The structures of sulfonyl chloride intermediates and sulfonamide dyes are confirmed by FTIR, ¹H NMR and mass spectrometry.To avoid the occurrence of chlorination at hydroxyl group ofβ-naphthol-containing structures, a reduced amount of SOCl₂ and some inert solvents are added to SOCl₂/DMF chlorination system for good selectivity of chlorination. Using SOCl₂/benzene/DMF as chlorination system and following above-mentioned method, three series of orange and redβ-naphthol-containing sulfonamide dyes are prepared. To avoid the influence of ammonolysis, alcoholysis and hydrolysis on molecular structure identification, in this paper, derivational estimation is utilized to confirm molecular structures ofβ-naphthol-containing sulfonyl chloride intermediates. Then the structures of corresponding sulfonamide dyes are also confirmed by FTIR, ¹H NMR and mass spectrometry.4-Amino-N, N-diethyl-benzenesulfonamide(4-8a) and 4-Amino-N-butyl-benzene-sulfonamide (4-8b) are synthesized from aniline by using a four-step process. Then two blue sulfonic acid-containing sulfonamide dyes(4-12a and 4-12b) are synthesized by use of 1-amino-4-bromoanthaquinone-2-sulfonate with 4-8a and 4-8b. After desulfonation of 4-12a and 4-12b, two blue hydrophobic anthaquinone-containing sulfonamide dyes(4-13a and 4-13b) are prepared. Their structures are confirmed by FTIR, ¹H NMR and mass spectrometry.Parts of aforementioned hydrophobic sulfonamide dyes with different colors are selected to apply to PET, unmodified PP and PLA fabrics in exhaust dyeing. In the dyeing results, as to azo dyes, secondary sulfonamide dyes are more suitable for dyeing of PET and unmodified PP fabrics than other types of sulfonamide dyes. The exhaustion of 2-21a-4 on PET fabric reaches 97.1%, its fastnesses to washing, sublimation and rubbing all reach 4-5 grade and its light fastness reaches 6 grade. The exhaustion of 3-8-3 on PP fabric also reaches 97.1%, its fastnesses to washing, sublimation are all above 4 grade. While tertiary sulfonamide dyes are more suitable for dyeing of PLA fabrics than other types of sulfonamide dyes. The exhaustion of 3-5a-6 on PLA fabric reaches 98.6%, its fastnesses to washing, sublimation and rubbing reach 4-5 grade, 4 grade and 3 grade respectively. In a word, sulfonamide dyes exhibit better color fastness properties on three sorts of hydrophobic fabrics, especially for sublimation fastness, in comparison with the dyes without sulfonamide group in their structures.