Synthesis and evaluation of novel antibacterial monoazo disperse dyes based on sulfonamide derivatives on polyester

Purpose - This paper aims to present the design and synthesis of a series of novel antibacterial monoazo disperse dyes based on sulfonamide derivatives to combine the dyeing and functional finishing steps on polyester into one process. Design/methodology/approach - The diazoniom salts of sulfonamides, namely, 4-amino-N-(2-pyrimidinyl) benzenesulfonamide, 4-amino-N-(4-methyl-2-pyrimidinyl) benzenesulfonamide and 4-amino-N-(4,6-dimethyl-2-pyrimidinyl) benzenesulfonamide were prepared and then coupled to N, N-diethyl aniline, N, N-dicyanoethyl aniline and N, N-dihydroxy ethyl aniline, respectively, to produce the dyes. Findings - The structures of the dyes were characterized using their spectral data (FTIR, 1H-NMR, UV-Vis) and elemental analysis. The results indicated that all the dyes exhibit positive solvatochromism in more polar solvents. Dispersion of the dyes was prepared in water and applied to polyester fabrics. The synthesized dye 3a which had good exhaustion on the fabric (89.98 per cent) and were tinctorially stronger (28899 l/mol. cm) showed higher visual colour yield (16.51). The antibacterial efficacy of the dyes was assessed, and they showed activity against both gram-positive and gram-negative bacteria but in different levels depending on their structures. Research limitations/implications - A simple way to combing functional finishing and dyeing in one process was successfully performed via design and synthesis of disperse dyes with an antibacterial moiety incorporated into dye molecules. The dyes were fully charaterized and evaluated on polyester. Originality/value - A series of novel antibacterial monoazo disperse dyes based on sulfonamide derivatives were synthesized. The authors studied their application for dyeing of polyester fabric. The dyes offered good results in terms of preparation, yield, purity, visual colour yield, fastness properties and activity against bacteria.