Preparation of high-performance monoazo disperse dyes bearing ester groups based on benzisothiazole and their dyeing performance on polyester fabrics.

To obtain high-performance disperse dyes, a series of azo disperse dyes containing different kinds of ester groups based on benzisothiazole were synthesized by the coupling reaction of diazotization of 3-amino-5-nitro [2,1] benzisothiazole with -substituted aniline compounds bearing different ester moieties. The structures of the synthesized dyes were evaluated using Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance techniques (H-NMR), and MS analysis. UV-Vis spectrophotometry methods were applied to study absorption maxima, molar extinction coefficients, and solvatochromic behaviors of the dyes, and time-dependent density functional theory (TD-DFT) simulations were applied to reveal the nature of the absorption spectrum properties. Polyester fabrics were colored using a high-temperature dyeing method under pressure, and the dyed fabrics exhibited deep and bright intense blue hues. In addition, excellent fastness properties, including washing fastness, sublimation fastness, rubbing fastness, and light fastness, were achieved.