Synthesis and application of bifunctional reactive dyes pyrazolo[1,2‐a] pyrazole 3‐carboxylic acid

Abstract

Purpose -The purpose of this paper is to synthesise, characterise and find out properties of some new bifunctional reactive azo dyes using pyrazolo[1,2-a]pyrazole 3-carboxylic acid fused systems as the chromophoric moiety, bearing good colour strength, lightfastness, and other favourable properties. Design/methodology/approach -The dyes are synthesised by diazotisation, coupling and cyclisation reactions. Firstly, synthesised 4-arylazo-1,5-dioxopyrazolo[1,2-a]pyrazole 3-carboxylic acid chromophoric moieties and coupled with diazonium salts having the aforementioned reactive groups, thus yielding the new target reactive. The synthesised dyes were applied to cotton and wool fabrics under the typical exhaust dyeing conditions and their dyeing properties were investigated. The structures of these dyes are characterised and confirmed by melting point, elemental analysis, infrared, ultraviolet-visible spectroscopy (UV/VIS) and nuclear magnetic resonance (1H-NMR) data. Findings -The wavelength of maximum absorptions, molar extinction coefficients are strongly dependent on the electron donating ability of the substituents on the coupling moiety. The absorption bands of these dyes move towards longer wavelength as the polarity of the solvents and electron density of substituents on the coupling moiety increase. The dyes applied on cotton and wool showed higher exhaustion and fixation values, colour yields and fastness properties.Research limitations/implications -The method developed provided a simple producing fused pyrazolo[1,2-a]pyrazole disazo chromophoric systems based on 4-arylazo-1,5-dioxopyrazolo[1,2-a]pyrazole 3-carboxylic acid as well as reactive dyes applied on wool and cotton dyes. Originality/value -In this paper, three series of pyrazolo[1,2-a]pyrazole derivatives dyes are synthesised and characterised. They have not been registered in the literature previously.

Synthesis and antibacterial activity of some novel nucleus N-aminorhodanine based bis monofunctional and bifunctional reactive dyes and their application on wool and cotton fabrics

“…The dye fixation (%F), the percentage of the exhausted dye chemically bonded on the fabric, was measured by refluxing the dyed sample in 50 percent aqueous DMF(20:1 LR) for 15 min to extract the unfixed dye [48]. This procedure was repeated until the extract was clear.…”

“…2 (2022) strength and light fastness. In addition, the gramnegative and gram-positive bacteria were tested on the dyed cotton fabric [40][41][42]. To impart antibacterial properties, reactive dyes with varying degrees of molecular weight chitosan were applied to wool fabric.…”

Optimization of Enzymatic Treatment and Reactive Dyeing of viscose fabric in One-bath Process

“…However, the large water consumption makes this process particularly not attractive on ecological grounds. In order to achieve effective production process, the fabric requires separately pretreatment bath to fabric has satisfactory levels of wetability, swelling and reduction of fibrillation tendency, which in turn, lead to a better dye uptake and increase the forces of dye-fiber interactions [11][12][13][14][15][16]. Moreover, several attempts have been made to sho exhaust two-bath processes of pretreatment and dyeing viscose into one-bath process.…”

Synthesis and application of novel reactive dyes based on Dimedone moiety

“…In the past, pyrazolo[1,2-a] pyrazole 3-carboxylic acid fused systems are sued as moiety to prepare new bifunction reactive azo dyes which give good strength, lightfastness, colour and other desirable properties. These dyes were used to dye wool and cotton fabrics [9,10]. Also, we have synthesised new bifunctional dyes bis (monochlorotriazine) based on tetrahydrobenzo[b]thiophene systems [11].…”