Synthesis of novel carbene dyes and investigation of their dyeing properties and reaction mechanism for various fabrics

Week interactions between traditional dye molecules and synthetic fibers requires addition of numerous chemical additives during the dyeing process, resulting in the generation of a significant amount of printing and dyeing wastewater, thereby causing environmental pollution. Herein, three novel carbene dyes containing diazirine were rationally designed, whose decomposition into carbenes at 145 degrees C subsequently forms covalent bonds with the C-H bonds present in the fibers. The structure-property relationships of the dyes were analyzed based on the results of density functional theory (DFT) calculations. Additionally, the calculations of Yoshida correlations demonstrated that all three dyes exhibit non-explosive properties, thereby indicating their feasibility for largescale production. The dyeing process of polyester (polyethylene terephthalate/PET), polypropylene (PP), aramid, spandex, and polyester/spandex (P/S) blended fabrics was performed using a non-aqueous solvent dyeing method without the addition of any additives, and the optimal dyeing and color fixation conditions were determined. The samples dyed with carbene dyes displayed similar K/S values compared to conventionally dyed samples, higher color fixation rates, and improved blended dyeing effects, and the reaction mechanism between the carbene dyes and the fibers was elucidated, which proved the versatility and environmental friendliness of the novel carbene dyes and non-aqueous solvent dyeing method. Furthermore, it is noteworthy that all of these dyed fabrics exhibited exceptional color fastness, highlighting the immense potential of the novel carbene dyes in promoting green production in the textile industry.