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Article
Publication date: 4 July 2016

G.H. Elgemeie, K.A. Ahmed, E.A. Ahmed, M.H. Helal and D.M. Masoud

The purpose of this study is to successfully implement microwave irradiation for the rapid synthesis of novel fluorescent dyes. The prepared dyes are then applied for printing of…

Abstract

Purpose

The purpose of this study is to successfully implement microwave irradiation for the rapid synthesis of novel fluorescent dyes. The prepared dyes are then applied for printing of polyester and polyamide by silk screen printing process.

Design/methodology/approach

A series of new N′-(methylene)-2-imino-2H-chromene-3-carbohydrazide derivatives 3a–r were synthesised in excellent yield and high atom economy by the Knoevenagel condensation of salicylaldehyde derivatives 1 and cyano-N′-methyleneaceto-hydrazide derivatives 2 in the presence of piperidine catalyst. The optical properties of the synthesised compounds were recorded; all of the compounds were found to be fluorescent in 1, 4-dioxane solution; they all emitted blue light (440-460 nm). This work shows that the optical properties strongly depend on the nature of the substituent, and indicate which type of substituent is favourable for a given application. It confirms that iminocoumarin derivatives could lead to a new generation of fluorescent probes, prone to easy modification of their chemical structure. These synthesised dyes are used to print polyester and polyamide fabrics using synthetic thickener in the printing paste for silk screen technique.

Findings

The structures of synthesised dyes were established and confirmed for the reaction products on the basis of their elemental analysis and spectral data (MS, IR and 1H-NMR). The suitability of the prepared dyestuffs for traditional printing on polyester and polyamide fabrics has been investigated. The prints obtained using the synthesised dyes were found to possess high colour strength and excellent overall fastness properties but relatively low light fastness.

Research limitations/implications

The synthesised fluorescent dyes were prepared by a simple reaction process in microwave. The optical properties for obtained dyes show include the fact that it will have various important applications. In addition, they were used for printing synthetic fabrics and were found to have good results.

Practical implications

The new fluorescent dyes’ system has excellent printing properties. Also they are superior in terms of yield, purity, colour strength and fastness properties which may lend them valuable commercial production.

Originality/value

The result of this work aimed to define the scope and limitation of the procedures for the synthesis of novel iminocoumarin dyes via a simple and economic way.

Details

Pigment & Resin Technology, vol. 45 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 7 November 2016

Galal H. Elgemeie and Doaa M. Masoud

This paper aims to focus on the most popular technique nowadays, the use of microwave irradiation in organic synthesis; in a few years, most chemists will use microwave energy to…

1266

Abstract

Purpose

This paper aims to focus on the most popular technique nowadays, the use of microwave irradiation in organic synthesis; in a few years, most chemists will use microwave energy to heat chemical reactions on a laboratory scale. Also, many scientists use microwave technology in the industry. They have turned to microwave synthesis as a frontline methodology for their projects. Microwave and microwave-assisted organic synthesis (MAOS) has emerged as a new “lead” in organic synthesis.

Design/methodology/approach

Using microwave radiation for synthesis and design of fluorescent dyes is of great interest, as it decreases the time required for synthesis and the synthesized dyes can be applied to industrial scale.

Findings

The technique offers many advantages, as it is simple, clean, fast, efficient and economical for the synthesis of a large number of organic compounds. These advantages encourage many chemists to switch from the traditional heating method to microwave-assisted chemistry.

Practical implications

This review highlights applications of microwave chemistry in organic synthesis for fluorescent dyes. Fluorescents are a fairly new and very heavily used class of organics. These materials have many applications, as a penetrant liquid for crack detection, synthetic resins, plastics, printing inks, non-destructive testing and sports ball dyeing.

Originality/value

The aim value of this review is to define the scope and limitation of microwave synthesis procedures for the synthesis of novel fluorescent dyes via a simple and economic way.

Details

Pigment & Resin Technology, vol. 45 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 2 November 2015

G.H. Elgemeie, K.A. Ahmed, E.A. Ahmed, M.H. Helal and D.M. Masoud

The study aims to synthesise new thiophene-based dyes by an efficient method using sodium a-cyanoketene dithiolates as starting components for synthesis of tetra-substituted…

Abstract

Purpose

The study aims to synthesise new thiophene-based dyes by an efficient method using sodium a-cyanoketene dithiolates as starting components for synthesis of tetra-substituted thiophenes, which act as a coupler for the synthesised dye. The synthesised dyes are applied for printing polyamide and polyester fabrics using the screen printing technique.

Design/methodology/approach

Treatment of 1 with carbon disulfide in alkaline medium forming disodium salt 2, which act as starting point for heterocyclisation to prepare these dye stuff 7. Sodium a-cyanoketene dithiolates 2 react with two moles of phenacyl bromide derivatives, forming alkylsulfanylthiophenes which react with the diazonium salt, forming the target dyestuff. These prepared dyes are used to print polyamide and polyester fabrics by using a synthetic thickener in the printing paste using screen-printing techniques.

Findings

The structure of synthesised dyes were established and confirmed for the reaction products on the basis of their elemental analysis and spectral data (IR and 1H-NMR). The suitability of the prepared dyestuffs for screen printing on polyamide and polyester fabrics has been investigated. The prints obtained from dyes possess high colour strength as well as excellent overall fastness properties.

Research limitations/implications

The diazo coupling reaction of the starting tetra-substituted thiophene 5 with diazotised aromatic amines resulted in the formation of the corresponding dye. The synthesised dyes were utilised in preparing a paste for polyester and polyamide fabric printing. In addition, both of the variations of the substituents on the synthesised dyes and the fastness properties were also studied.

Practical implications

The synthesised dyes are superior in terms of yield, purity, colour strength and fastness properties, which lead to valuable achievements for commercial production.

Social implications

The synthesised dyes are superior for application in fabrics.

Originality/value

The synthesis for novel thiophene-based dye stuff for application in printing properties on polyester and polyamide fabrics and study their fastness properties.

Article
Publication date: 5 May 2015

G.H. Elgemeie, K.A. Ahmed, E.A. Ahmed, M.H. Helal and D.M. Masoud

The purpose of this paper is to synthesize some novel 2-amino-6,6-dimethyl-9-phenyl-3-(phenyldiazenyl)-6,7-dihydropyrazolo-[5,1-b]quinazolin-8(5H)-one derivatives by…

Abstract

Purpose

The purpose of this paper is to synthesize some novel 2-amino-6,6-dimethyl-9-phenyl-3-(phenyldiazenyl)-6,7-dihydropyrazolo-[5,1-b]quinazolin-8(5H)-one derivatives by multi-component one-pot reaction using a microwave as a new tool for green chemistry.

Design/methodology/approach

An equimolor from arylazopyrazole, 5,5-dimethyl-1,3-cyclohexanedione (dimedone) and benzaldehyde derivatives was dissolved in Dimethylformamide (DMF) to be irradiated in a microwave for 15 minutes; after completion of the reaction, as indicated by Thin layer chromatograph (TLC), the reaction mixture was poured into ice water, filtered and then crystallized with an appropriate solvent.

Findings

The structure of the synthesized dyes was established and confirmed for the reaction products on the basis of their elemental analysis and spectral data (MS, IR and 1H-NMR). These prepared dyes were used to print polyester and polyamide fabrics using synthetic thickener in the printing paste for the silk screen technique. The synthesized dyes are superior in terms of yield, purity, color strength and fastness properties and will lead to valuable achievements for commercial production.

Originality/value

An efficient method for synthesis of pyrazoloquinazolinone dyes was designed. The novel procedure features short reaction time, moderate yields and simple workup. The authors studied its application in printing polyester and polyamide fabrics.

Details

Pigment & Resin Technology, vol. 44 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 7 November 2008

M.H. Helal, G.H. Elgemeie and D.M. Masoud

This paper's aim is to evaluate the dyeing performance of newly designed azo dye system based on thiazole substituted for improved dyeing when applied to synthetic fibres.

Abstract

Purpose

This paper's aim is to evaluate the dyeing performance of newly designed azo dye system based on thiazole substituted 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 thiazole as the coupling component. The heterocyclic moiety was coupled with diazotised aromatic amines to afford the respective azo or hydrazono systems. 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 evaluated.

Findings

The novel systems were designed so that the functionalities located on the heterocyclic ring afforded structure modification that led not only to good dispersion but also to improved adherence on the fibre. The location of the sites led to constructing 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 new dyes. In addition, the variations in substituents and location of sites on the heterocyclic core could also be studied.

Practical implications

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

Originality/value

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

Details

Pigment & Resin Technology, vol. 37 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 18 September 2007

M.H. Helal, G.H. Elgemeie and D.M. Masoud

This paper aims to synthesize some new heterocyclic disperse azo dyes and their application in dyeing of polyester and polyamide fabrics.

Abstract

Purpose

This paper aims to synthesize some new heterocyclic disperse azo dyes and their application in dyeing of polyester and polyamide fabrics.

Design/methodology/approach

Pyrazolopyrimidine derivatives containing arylazo function by the reaction of 3,5‐ diaminopyrazole with ketene dithioacetals were prepared. The prepared dyestuffs are established using elemental analysis, IR measurements, 1H‐NMR and Mass spectra.

Findings

2,5‐diamino‐3‐arylazo‐N‐aryl‐6‐carboxamide‐7‐methylthio‐pyrazolo[1,5‐a]pyrimidine have been synthesized by the simple method. The dyed fabrics have a very good (4‐5) to excellent (5) results toward washing, perspiration, and rubbing fastness properties. The dyes are superior in terms of preparation and fastness properties.

Research limitations/implications

The disperse azo dyes used in this paper were synthesized via a step‐wise pathway leading to the new azo dyes. In addition, the variations in substituents and sites of location on the heterocyclic moiety could also be studied.

Practical implications

The new azo dye systems based on substituted pyrazolopyrimidine provided a series of azo dyes with improved dyeing properties. The dyes are superior in terms of yield, purity, colour strength, and fastness properties and will lead to valuable achievements for commercial production.

Originality/value

The synthesized disperse azo dyes are superior in terms of preparation, yield, purity, and fastness properties.

Details

Pigment & Resin Technology, vol. 36 no. 5
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 2 March 2015

G.H. Elgemeie, K.A. Ahmed, E.A. ahmed, M.H. helal and D.M. Masoud

– This paper aims to synthesise coumarine flourescent dyes from a cheap material in a very short time with a very high yield, and by using a clean green chemistry.

Abstract

Purpose

This paper aims to synthesise coumarine flourescent dyes from a cheap material in a very short time with a very high yield, and by using a clean green chemistry.

Design/methodology/approach

Efficient microwave synthesis for some novel iminocoumarins starts from the reaction of p-phenyl-enediamine and ethyl cyanoacetate followed by cyclocondensation with salicylaldehyde derivatives.

Findings

The synthesized iminocoumarine compounds were characterized by spectroscopic methods. Absorption and fluorescence spectra of the compounds were also recorded. All compounds were fluorescent in 1,4-dioxane solution, they all emitted blue light (440-460 nm). The printing properties were studied, and their applications on printing polyester and polyamide fabrics were studied by silk screen printing.

Originality/value

The authors designed efficient microwavel synthesis for some novel iminocoumarine derivatives; The novel procedure features short-reaction time, moderate yields and simple workup; All compounds were fluorescent in 1,4-dioxane solution, and they all emitted blue light; The authors studied their application in printing polyester and polyamide fabrics.

Details

Pigment & Resin Technology, vol. 44 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 8 February 2021

Ebtsam Abdelmowla Ahmed, Galal Elgemeie and Kawther Abd-Elzaher Ahmed

This study aims to represent a successful simple method for the synthesis of some novel dyes based on thiazole derivatives and their applications in textile printing.

Abstract

Purpose

This study aims to represent a successful simple method for the synthesis of some novel dyes based on thiazole derivatives and their applications in textile printing.

Design/methodology/approach

2-(benzo[d]thiazol-2-ylmethyl)thiazol-4(5H)-one compound is prepared by convention heating and microwave technique then used as a coupling agent, which reacts with different diazonium Salt to form diazo dyes.

Findings

The synthesized diazo dyes are confirmed via spectral data (IR,1H-NMR, 13C-NMR and Mass spectra). The dyes are used to print polyester fabric. The obtained results clarified that the prints have good color strength, brilliant color and highly durable antibacterial activity.

Originality/value

The authors designed efficient synthesis for some novel thiazolone dyes. The novel procedure features short-reaction time, very good yields and a simple workup. The authors studied the antibacterial activity and their application in printing polyester fabrics.

Details

Pigment & Resin Technology, vol. 51 no. 1
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 18 June 2019

Sevinç Sevim Kahya, Yasemin Sönmez, Güngör Gündüz and Bora Mavis

The purpose of this paper is to enhance the limited fluorescence of mica titania (MT) effect pigments by coating them with peripherally substituted zinc phthalocyanines (ZnPc).

Abstract

Purpose

The purpose of this paper is to enhance the limited fluorescence of mica titania (MT) effect pigments by coating them with peripherally substituted zinc phthalocyanines (ZnPc).

Design/methodology/approach

The effects of deposition medium, temperature, time, initial organic pigment/MT ratio on deposition behaviour and efficiencies were investigated separately for ZnPc, nitro (TNZnPc) and amino (TAZnPc) substituted ZnPc’s.

Findings

TNZnPc could be deposited in the form of well-defined crystals on MT with per cent 64 ± 5 efficiency in chloroform at 50°C within 5 h and the amount deposited was linearly dependent on the initial TNZnPc concentration. TNZnPc fluorescence emissions, which appear mainly at 460 and 685 nm in pure pigments, could be observed in combination with MT (MT-TNZnPc) as well. A spectral analysis on the non-overlapping region of the spectrum with two different excitations (385 and 630 nm) revealed that, respectively, up to threefold to sixfold increase is possible to attain, depending on the excitation wavelengths.

Research limitations/implications

Efficiency of deposition could not be taken above per cent 11 ± 4 with TAZnPc. Although ZnPc could be deposited with per cent 57 ± 3 efficiency, the pigment was not effective in imposing its fluorescence characteristics over MT.

Originality/value

Combining inorganic effect pigments with organic dye molecules is an idea that has been elaborated mainly for producing different colour effects and stabilization of dye molecules against agglomeration. Here, for the first time, it is used to enhance the fluorescence of the effect pigments.

Details

Pigment & Resin Technology, vol. 48 no. 4
Type: Research Article
ISSN: 0369-9420

Keywords

Open Access
Article
Publication date: 1 February 2023

Rahabhi Mashapure, Brighton Nyagadza, Lovemore Chikazhe, Gideon Mazuruse and Precious Hove

The main purpose of this research is to investigate factors influencing rural women entrepreneurship development and sustainable rural livelihoods in Manicaland province of…

12627

Abstract

Purpose

The main purpose of this research is to investigate factors influencing rural women entrepreneurship development and sustainable rural livelihoods in Manicaland province of Zimbabwe.

Design/methodology/approach

A quantitative research was conducted in Manicaland province in Zimbabwe. Data were collected through structured questionnaires from 400 women entrepreneurs in various sectors. The participants were in vegetable vending, operating clothing flea markets and cross border trading. A self-administered structured questionnaire was used to collect data from respondents. Structural equation modeling in SmartPLS version 3 was used to test the research hypotheses.

Findings

The study established that women entrepreneurship is driven by financial factors, positive environmental factors, positive psychological factors as well as positive sociological factors for a sustainable rural livelihood.

Research limitations/implications

It is clear that if the discovered challenges are not addressed, sustainability of women entrepreneurship will remain a dream.

Practical implications

The study came up with strategies for improving women entrepreneurship activities. Future research can be done in other areas of provinces to avoid generalization challenges.

Social implications

Many challenges hinder the sustainability of women entrepreneurship. Major impediments to women entrepreneurship comprises inadequate support from government schemes, patriarchal societal structure of the community, lack of relevant entrepreneurial knowledge to manage businesses, lack of collateral security to access funding, time limitation or role conflict to balance family pressures and business.

Originality/value

The study recommends proper entrepreneurship education and training, supportive government schemes and access to network affiliation/connection to sustain women entrepreneurship.

Details

Arab Gulf Journal of Scientific Research, vol. 41 no. 4
Type: Research Article
ISSN: 1985-9899

Keywords

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