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The purpose of this study is to provide effective and environmental-friendly corrosion inhibitors derived from graphene oxide for Q235 steel.

Nontoxic and environment-friendly 4-aminobenzoic acid was used to functionalize graphene oxide via amidation and diazotization. The obtained amidation 4-aminobenzoic acid functionalized graphene oxide (PAGO) and diazotization 4-aminobenzoic acid functionalized graphene oxide (PDGO) were characterized by FTIR, Raman and TEM, while the inhibition efficiencies were analyzed by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP). Furthermore, theoretical inhibition efficiencies were investigated by density functional theory (DFT) approach.

At a concentration of 40 ppm, the maximum inhibition efficiency of PAGO and PDGO were 97.90% and 96.72% in EIS measurement, respectively, which were in accordance with PDP data. Moreover, experimental results were supported by DFT-based quantum chemical calculation.

Environmental-friendly PAGO and PDGO were synthesized successfully. The synthetic inhibitors exhibited excellent inhibition efficiencies in EIS and PDP measurements. Furthermore, a computational study using DFT supported the trend that PAGO was better inhibitor than PDGO.

The synthesis and chemistry of nitrogen heterocyclic azo compounds have been extensively studied. Many derivatives of this type were proved to be excellent dyes. Presents a systematic and comprehensive survey of all recently synthesised nitrogen heterocyclic azo dyes according to dyeing methods.

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.

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.

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.

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

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.

The purpose of this paper is to use the bio-based resource as the starting material for the synthesis of azo dye. Cardanol is one of the most used bio-based resources for carrying out the synthesis of various compounds having numerous end applications. The study presents an attempt to develop an azo dye from Cardanol having end applications in pH-responsive dyes.

The cardanol was sulfonated to block the para position by which ortho positioned hydroxyl group after diazotization and coupling will provide necessary pH-sensitivity. The diazotization of two naphthalene derivatives, i.e. 1-naphthol-8-amino-3,6-disulfonic acid (H-acid) and 7-amino-4-hydroxy-2-naphthalene sulfonic acid (J-acid) was carried out using the standard practice, and the diazotized compounds were coupled with the sulfonated cardanol. The obtained dyes were characterized by Fourier transform infrared, nuclear magnetic resonance, carbon-hydrogen-nitrogen-sulfur analysis and hydroxyl value. The colour properties were checked using UV-vis spectrophotometry and density functional theory, while thermogravimetric analysis was used for the thermal degradation studies of both the dyes.

Water-soluble cardanol-based azo dyes were prepared successfully having good thermal stability, and the obtained results are being presented in this paper.

The originality lies between the use of cardanol as a bio-based resource for the synthesis of azo-dye and the obtained azo-dye has the pH-sensitivity.

Aqueous sodium chloride solution, containing benzamide was electrolysed (pH = 2), using platinised titanium anode and graphite cathode. The filtrate of the reaction mixture (pH = 4.5) was diazotised and coupled with α‐naphthol in NaOH and also with β‐naphthol in NaOH. Dyes were produced. These dyes were matched with the standard dyes prepared from aniline. Uv‐visible absorption spectral study reveals that the dyes produced are slightly different from the standard dyes. During the course of the reaction benzamide is converted into aniline with a long chain polymeric unit having a free amino end; and/or a polymeric unit which generates a free amino end during the process of diazotisation.

Benzamide has been made to undergo Hofmann rearrangement, in the presence of hypochlorite (OCl^‐) generated in situ, by the electrolysis of sodium chloride solution using platinised titanium anode and graphite cathode. The product is not a pure primary amine, namely aniline; but a polymeric aniline derivative is produced. It has a free amino end; and/or a free amino end is generated during the process of diazotisation. The product has been diazotised and coupled with naphthols to give dyes. The nature of the dyes have been analysed by uv‐visible spectral studies. The dyes are slightly different from the dyes prepared from pure aniline.

The purpose of this paper is to synthesise, characterise and find out properties of some new arylazopyridone disperse dyes, bearing different substituents on coupling component of the dyes.

The dyes are synthesised by diazotisation, coupling and cyclization reactions, starting from various aryldiazonium salts and different β‐diketoesters followed by condensation with cyanoacetamide. 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. Their absorption properties in different solvents are also investigated.

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. These dyes are chromophorically strong as evidenced by molar extinction coefficient in solvents.

In this paper, four series of arylazopyridone dyes (21 dyes) are synthesised and characterised. They have not been registered in the literature previously.

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.

The TAN and TBN determination in oils according to DIN/ASTM is an abstraction, even at times an anathema, as far as many analysts are concerned owing to its slow and sluggish course. The same is true of the diazotization of aromatic amines, the coupling titration of, for example, phenols as well as the titanometric determinations of organic nitro compounds in dyestuff chemistry. The content determinations of these species are mostly associated with problems involving the potentiometric acquisition of the equivalence point. The highly sensitive, modern titrators such as the METROHM Titroprocessors allow the evaluation of extremely small and flat equivalence points. Although this feature is welcome in principle, it is, however, now always desirable with many arkward redox titrations. In cases of slow adjustment of the equilibrium at the electrodes, additional, undesirable “ghost end points” are often found. The new software of the 686 Titroprocessor from METROHM thus incorporates, with immediate effect, the MET method (Monotonic Equivalence point Titration, i.e. addition of the titrant in fixed volume steps, programmable between 0.01 and 9.99ml). Under kinetically difficult conditions and/or with inhibited reactions, this allows transfer of the measured value after a fixed waiting time or in accordance with a drift criterion set in advance. The monotonic reagent addition alone justifies the new software yet thanks to the reduced sensitivity towards changes in the fine structure of the curve, improved results are found in the equivalence point calculation of titrations suffering equilibrium disturbance. The evaluation is performed using a “FORTUIN” procedure modified by METROHM.

This paper aims to synthesise, characterise and find out the properties of a model dye for convenient union dyeing of wool, polyester and wool/polyester blend fabric compared with C.I. Disperse Yellow 23. The reactive disperse dye was prepared containing sulphatoethylsulphone (SES) as a reactive group. The dye was synthesised by diazotization and coupling reaction. Firstly, we synthesized azo dye intermediate I using 1-aminobenzene-4-sulphatoethylsulphone diazotized and then coupled it with aniline. The synthesized azo dye intermediate I was diazotized and coupled with phenol to give dye 2. Different factors affecting the dyeability and fastness properties of SES dye 2 were thoroughly investigated on wool, polyester and wool/polyester blend fabrics in comparison with C.I. Disperse Yellow 23 dye 1. Maximum exhaustion and total fixation yield using sulphatoethylsulphone (SES) dye 2 were achieved on wool fabric at neutral pH 7. The dye showed high dyeing performance due to its nonionic reactive VS derivative. The dyeing results indicate high quality dyeing properties