A series of azo disperse dyes was synthesised and the purified, synthesised dyes were characterised by proton nuclear magnetic resonance, thin-layer chromatography and melting point measurement. The spectroscopic properties of the dyes in solution were studied by dissolving the dyes in ethyl acetate and methyl benzoate. These were seen as mimicking the environment of the dye when inside dyed poly(lactic acid) and poly(ethylene terephthalate), respectively. Reflectance spectra of the dyes on both polyester substrates were also measured in order to correlate with the spectroscopic properties of the dyes in solution. The absorbance spectra of the dyes in solution exhibited a hypsochromic (lower wavelength of maximum exhaustion) shift when dissolved in ethyl acetate, compared with methyl benzoate. The occurrence of this yellow shift was attributed to the lower polarity of ethyl acetate compared with methyl benzoate. The colour of the dyes in ethyl acetate solution was also brighter and stronger (higher molar extinction coefficients) than that in methyl benzoate. Most of the synthesised dyes exhibited high levels of exhaustion onto the two polyester fabrics. However, the visual colour yields, for those dyes having approximately the same high level of exhaustion, were different, the dyed poly(lactic acid) being stronger (higher K ⁄ S value) as well as being yellower and a trace brighter than the dyed poly(ethylene terephthalate). This difference correlated well with the solvatochromic study of the dyes in ethyl acetate and methyl benzoate solution.
A series of azo disperse dyes was synthesized using 4-nitro aniline and 2-chloro-4-nitro aniline as diazo components. The coupling components were N,N-diethyl aniline, N,N-bis-β-hydroxyethyl aniline, N,N-bis-β-acetoxyethyl aniline, N,N-diethyl-m-toluidine, N,N-bis-β-hydroxyethyl-m-toluidine and N,N-bis-β-acetoxyethyl-m-toluidine. The structures of the synthesized dyes were confirmed by TLC, 1H NMR and elemental analysis. The spectroscopic properties of the dyes when dissolved in the organic solvents viz. ethyl acetate and methyl benzoate, were investigated. The absorption spectra of the dyes showed a bathochromic shift when the polarity of the solvents increased. In addition, the substituent groups on the dye structures influenced the spectroscopic properties of the dyes. The dyeing properties of the dyes on poly(ethylene terephthalate) and poly(lactic acid) fabrics were also studied. The dyes exhibited a slight difference in shade on the two polyester fabrics. Heat and light fastness properties of the dyed fabrics were also examined.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.