Synthesis of Nitroso-Based Bis-Azo Dyes And Their Dyeing Properties For Polyethylene Terephthalate And Polyamide

Abstract

The aim of this work is the synthesis of new azo nitroso-based dispersed dyes with better dyeing properties on synthetic fibers. In this regard, bis-azo nitroso naphthalene dyes were synthesized via the diazo coupling reactions of 4-nitroaniline with 1-hydroxy-2-nitrosonapthalene. Products formed were characterized by 1 H and 13 C NMR.Absorption values in the UV-vis spectra of the derivatives under study were quite close and they exhibited multiple maxima in the 386 -513nm range. The dyeing process, dye exhaustion on polyethylene terephthalate (PET) and polyamide 6 (nylon 6) fabrics, and the durability of the dyes on the textile substrates were evaluated. It was found that the light fastness ratings of the dyed fabrics could reach grade 6/7 to 7, while washing fastness gave excellent values of grade 5 rubbing and perspiration fastness grades were rated at 4/5 to 5 on the International Geometric Scale. The results obtained suggested that the dyes could be used as disperse dyes on synthetic polymers fibres.

Preparation and evaluation of antimicrobial thiadiazol azo disperse dyes as colored materials in digital transfer printing ink for printing onto polyester fabric

“…The high lightfastness of dyes 2 and 3 on polyester fabric may be due to the electron-donating OH and NH 2 groups, respectively. In general, the prepared dyes exhibited satisfactory resistance to photo fading (Augustine, 2020).…”

“…The agreement of these results may be attributed to an increase in the large molecular size of the dye molecules as well as the good diffusion of the dye molecules inside the fabrics. The high rating for change of color (Grade 4/5 – 5) of the perspiration fastness of the dyes under both acid and alkaline conditions implied that the dyes were relatively stable concerning pH changes (Augustine, 2020).…”