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Article
Publication date: 28 June 2013

Fatma Ali Mohamed and Rafaat Melad Mohareb

The purpose of this paper is to synthesise, characterise and find out properties of some new bifunctional dyes bis (monochlorotriazine) using tetrahydrobenzo[b]thiophene systems…

Abstract

Purpose

The purpose of this paper is to synthesise, characterise and find out properties of some new bifunctional dyes bis (monochlorotriazine) using tetrahydrobenzo[b]thiophene systems as the chromophoric moiety, bearing good colour strength, lightfastness, and other favourable properties.

Design/methodology/approach

The novel reactive dyes were prepared, containing bis monochlorotriazine as reactive groups. The dye is synthesised by diazotization and coupling reactions. Firstly the authors synthesised the ethyl 2‐amino 4,5,6,7‐tetrahydrobenzo[b]thiophen‐3‐carboxylate chromophoric moiety compound which in turn underwent diazotization and coupling then diazotized and coupled reaction with either 1‐amino‐8‐naphthol‐3,6‐disulphonic acid (H‐acid) and or 2‐amino‐8‐naphthol‐6‐sulphonic (γ acid) to give the monoazo dye intermediates compounds. The latter products reacted with 2,4,6‐trichloro‐1,3,5‐triazine in 1:1 molar ratio afforded, via nucleophilic displacement when subjected to condensation 2,4,6‐trichloro‐1,3,5‐triazine in 1:1 molar ratio afforded via nucleophilic displacement, which reacted with 1,4‐phenylenediamine in 2:1 molar ratio to give reaction with the 1,4‐phenylenediamine in 2:1 molar ratio, the bisazobifunctional bismonochlorotriazine reactive dyes.bisazo bifunctional bismonochlorotriazine reactive dyes thus yielding the new target reactive. The synthesised dyes were applied onto cotton fabric 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 homobifunctional (bis MCT) dyes showed higher exhaustion and fixation values, colour yield and fastness properties.

Practical implications

The described method showed the synthesis of bis monochlorotriazines derived from the tetrahydrobenzo[b]thiophene derivative 3 followed by their application towards cotton fabric.

Social implications

Social implications are to prepare new reactive dyes having higher fastness and uses for dyeing cotton which is the commonest fabric use.

Originality/value

In this work, the novel reactive dyes derived from the tetrahydrobenzo[b]thiophene derivative 3 were synthesized and their structures were based on the analytical and spectral data. Such a group of compounds are considered to be excellent reactive dyes with different colour shades.

Details

Pigment & Resin Technology, vol. 42 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 1 August 2014

F. A. Mohamed and R. M. Mohareb

Ethyl 2-diazo-4, 5, 6, 7-tetrahydrobenzo[b] thiophene-3-carboxylate is reacted with malononitrile to give a hydrazone derivative. The latter product is reacted with…

Abstract

Ethyl 2-diazo-4, 5, 6, 7-tetrahydrobenzo[b] thiophene-3-carboxylate is reacted with malononitrile to give a hydrazone derivative. The latter product is reacted with 1-diazobenzene-4-β-sulphatoethylsulphone (PABSES) to give a disperse dye. The dye is synthesised by diazotisation and coupling reactions. First, it is synthesised with the chromophoric moiety of ethyl 2-hydrazomalononitrilo-4,5,6,7-tetrahydrobenzo[b] thiopheen- 3-carboxylate and coupled with diazonium salts that have the aforementioned reactive groups, thus yielding the new target reactive. The synthesised dye is applied onto wool, polyester and wool-polyester (blend) fabrics under typical exhaust dyeing conditions and their dyeing properties are investigated. The structure of this dye is characterised and confirmed by melting point, elemental analysis, infrared, ultraviolet-visible spectroscopy (UV/VIS) and nuclear magnetic resonance (1H-NMR) data. The dyeing of polyester, wool and polyester/wool blend fabrics with a reactive disperse dye gives very good build up and fastness properties by using a nonionic vinylsulphone (VS) derivative, which increases the substantivity of the dye towards wool fabric. Maximum exhaustion as well as total fixation efficiency by using a sulfatoethylsulfone (SES)-based dye on wool fabric is achieved at a neutral pH of 7. This feature of the dye structure significantly improves the union dyeing of wool/polyester blend fabrics with very good build up and fastness properties.

Details

Research Journal of Textile and Apparel, vol. 18 no. 3
Type: Research Article
ISSN: 1560-6074

Keywords

Article
Publication date: 12 September 2008

H.Z. Shams, M.H. Helal, I.M. Samir and R.M. Mohareb

The purpose of this paper is to evaluate the dyeing performance of newly designed and synthesised azo dye systems based on polyfunctionally substituted oxopyridine core for…

Abstract

Purpose

The purpose of this paper is to evaluate the dyeing performance of newly designed and synthesised azo dye systems based on polyfunctionally substituted oxopyridine core for improved dyeing when applied to synthetic fibres.

Design/methodology/approach

For improved dyeing qualities, various azo dye systems were synthesised based on polyfunctionally substituted oxopyridine core as the coupling component. The heterocyclic moiety was coupled with diazotized aromatic amines or diazotized tetrahydrobenzothiophenes to afford the respective azo or hydrazono systems. Other counterparts were obtained via treatment with different reagents. The structure of the novel systems was elucidated based on elemental analysis and spectral data. Dyeing performance, electronic spectra and optical properties were characterised based on UV and K/S measurements. Fastness properties were also evaluated.

Findings

The novel systems were designed so that the functionalities located on the heterocyclic core afforded structure modification that led not only to good dispersion but also to improved adherence on the fibre. The sites of location led to construction of a resonating system with higher electron mobility and higher absorption maxima.

Research limitations/implications

The azo dyes, used in the present context were synthesised via a step‐wise pathway leading to different systems of dyes. In addition, the variations in substituents and sites of location on the heterocyclic core could also be studied.

Practical implications

The novel azo dye systems based on polyfunctionally substituted oxopyridine core provide a simple practical access to a series of azo dyes with improved dyeing properties. The availability of starting materials, the simplicity and efficiency for production in good yields and high‐purity can lead to valuable achievements for commercial production.

Originality/value

The designed and synthesised azo dye systems could find numerous applications as disperse dyes in the fields of dyeing, printing and surface coating. Moreover, the systems could find applications as reactive dyes for wool, silk and cellulosic fibres.

Details

Pigment & Resin Technology, vol. 37 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 25 October 2018

Amira E.M. Abdallah and Rafat M. Mohareb

This work aims to synthesize a series of novel acyclic and/or heterocyclic systems, as precursors for dyes with potential antimicrobial activity that could be used for…

Abstract

Purpose

This work aims to synthesize a series of novel acyclic and/or heterocyclic systems, as precursors for dyes with potential antimicrobial activity that could be used for simultaneous dyeing and antimicrobial textile finishing. Thus, a series of novel pyridine, thiophene and pyrazolo[3,4-b]pyridine derivatives were synthesized, and their antimicrobial and textile finishing properties were studied and evaluated.

Design/methodology/approach

The synthesis, structure elucidation and antimicrobial activities of the newly synthesized compounds based on 4,4-dicyano-3-phenyl-but-3-enoic acid phenylamide (1) were demonstrated. The minimal inhibitory concentration in μg/mL of the compounds showed significant antimicrobial activity against most of the tested organisms. On the other hand, their spectral characteristics and fastness properties were measured and evaluated. Antimicrobial activities of the dyed fabrics in terms of inhibition zones (mm) were measured and evaluated.

Findings

A series of novel heterocyclic compounds (Schemes 1-3) were synthesized based on starting material (1). Compounds (1), 2, 4a, 8a and 9c exhibited comparable or even higher antibacterial activities than the selected standards (ampicillin), while compounds 2, 3c, 3d, 4a and 8b revealed higher antifungal activities than the selected standard (cycloheximide). On the other hand, some dyes showed high antimicrobial evaluation on the dyed fabrics (nylon 66, acetate and polyester) expressed as size (mm) of inhibition zones (Tables I-IV).

Practical implications

Results revealed that many hydrazo and azo derivatives were synthesized from some pyridines and thiophenes. The antimicrobial evaluation and textile finishing of the newly synthesized products revealed significant and potent values of antimicrobial activity.

Originality/value

All the synthesized compounds were novel and most of them exhibited higher antimicrobial activities than the selected standards antibiotics, thus are valuable for simultaneous dyeing and antimicrobial functional finishing of textile fabrics.

Details

Pigment & Resin Technology, vol. 48 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 8 May 2018

Fatma A. Mohamed, Saadia A. Abd El-Megied, Mahmoud S. Bashandy and Hassan M. Ibrahim

This study aims to synthesise and characterise new reactive dyes based on thiazole derivatives which act as chromophoric moieties. These dyes were applied to cotton fabric…

Abstract

Purpose

This study aims to synthesise and characterise new reactive dyes based on thiazole derivatives which act as chromophoric moieties. These dyes were applied to cotton fabric, resulting in the dyed fabrics exhibiting good colour strength, light fastness and other fastness properties. The antibacterial activity of the dyed cotton fabric was evaluated against gram-negative and gram-positive bacteria.

Design/methodology/approach

The dyes were synthesised in two steps. First, the coupling compound was formed by adding H-acid solution to cyanuric chloride in an ice bath at pH 5 then adding 4-aminobenzenesulphonic acid portion-wise at room temperature and at pH 6-7. Second, different diazonium salts 4-phenylthiazol-2-amine (2a) and 4-(4-methoxyphenyl) thiazol-2-amine (2b) were coupled with the coupling compound at pH 5. The resultant monochlorotriazine (MCT)-reactive dyes (6a, 6b) were formed. The synthesised dyes were applied onto cotton fabric under typical exhaust dyeing conditions and their dyeing properties were investigated.

Findings

High antimicrobial activity, dye exhaustion and fixation yield on cotton fabric were recorded for each dye. All dyes showed high stability against washing, rubbing, perspiration and light fastness.

Research limitations/implications

Dyeing of cotton fabric with these dyes which have higher fastness, higher exhaustion and higher antibacterial activity is considered one of the most important reactive dyes species.

Practical implications

The preparation procedure showed the synthesis of the novel MCT-reactive dyes derived from thiazole derivatives followed by the application of these dyes on cotton fabrics.

Social implications

Use of reactive dyes will bring a number of benefits to society including higher fastness and higher antibacterial activity so, and these dyes can be used for dyeing cotton.

Originality/value

In this work, the new reactive dyes derived from thiazole derivatives were synthesised and their structures were confirmed by the analytical and spectral data. Such compounds are considered to be excellent reactive dyes with different colour shades and higher antibacterial activity.

Details

Pigment & Resin Technology, vol. 47 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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