Design, Synthesis, Characterization, and Antimicrobial Properties of New Azo Disperse Dyes Incorporating Quinazolinone-Pyrazolone Moieties and Their Applications for Dyeing of Polyester Fabrics

The current study outlines a straightforward and efficient method for creating new quinazolinone disperse dyes based on pyrazolone moieties, starting with quinazolinone and a variety of substituted pyrazolone as couplers. The synthesized dyes were characterized using a variety of spectroscopic and analytical methods. The synthesized dyes' ultraviolet–visible spectra showed bands brought on by several molecular transitions. We investigated in detail the multifunctional characteristics such color representation, dyeing duration, concentration, pH, buildup, and fastness properties of the dyed samples. Fastness properties and colorimetric data showed satisfactory results, demonstrating the effectiveness of these dyes in dyeing polyester fabrics. A pH of 5 and a dyeing temperature of 130 °C were the ideal conditions for dyeing polyester fabrics. Additionally, an ultraviolet protection factor test was performed on the dyed fabrics, and the results showed that these dyes provide the best UV protection. These dyes are suitable for industrial dyeing applications since they are easy to manufacture and scale up. Additionally, in-vitro testing was done to determine the dyes' antibacterial effectiveness against various bacteria and fungi. The antibacterial activity of the dyes was moderate to very good against both Gram-positive and Gram-negative bacteria, as well as fungi.