Synthesis and application of novel disazo pyrazolo[1,2‐a]pyrazole reactive dyes
Abstract
Purpose
The purpose of this paper is to evaluate the efficiency of modifying reactive azo dyes using pyrazolo[1,2‐a]pyrazole fused systems as the chromophoric moiety which could satisfy many and varied criteria drawn from economic, synthetic, physicochemical and fastness properties.
Design/methodology/approach
Six novel heterocyclic disazo reactive dyes were prepared, containing monofunctional sulphatoethylsulphone (SES) and hetero‐bifunctional monochlorotriazine (MCT)/SES reactive groups. Dyes intermediates based on 4‐arylazo‐1,5‐dioxopyrazolo[1,2‐a]pyrazole chromophoric moieties are initially synthesised and coupled with two different diazonium salts having the aforementioned reactive groups, thus yielding the new target reactive dyes. The synthesised dyes are applied to cotton, wool and silk fabrics under the typical exhaust dyeing conditions and their dyeing properties were investigated.
Findings
The results assessed for dyeing indicate high‐quality dyeing properties. However, the heterobifunctional MCT/SES dyes showed higher exhaustion and fixation values, colour yields and fastness properties than those of the monofunctional SES dyes.
Research limitations/implications
The method developed provided a simple and practical procedure for producing fused pyrazolo[1,2‐a]pyrazole disazo chromophoric systems that afford valuable reactive dyes. In addition, the dyes intermediates based on 4‐arylazo‐1,5‐dioxopyrazolo[1,2‐a]pyrazole as well as their disazo counterparts could be applied as acid dyes to wool and silk.
Originality/value
The method for producing novel disazo reactive dyes could find numerous applications for affording a variety of reactive dyes with different binding linkages and structural reactivity. These could be valuable as reactive dyes with different colour shades.
Keywords
Citation
Shams, H.Z., Youssef, Y.A., Mohamed, F.A., El‐Zawahry, M.M., Helal, M.H. and El‐Kharadly, E.A. (2009), "Synthesis and application of novel disazo pyrazolo[1,2‐a]pyrazole reactive dyes", Pigment & Resin Technology, Vol. 38 No. 6, pp. 372-379. https://doi.org/10.1108/03699420911000628
Publisher
:Emerald Group Publishing Limited
Copyright © 2009, Emerald Group Publishing Limited