Synthesis of a novel fluorescent coloured copolymer based on 4‐butylthio‐1,8‐naphthalimide

A novel fluorescent coloured copolymer based on naphthalimide was prepared. Acenaphthene was brominated and oxidised to prepare 4‐bromo‐1,8‐naphthalic anhydride and further reacted with butanethiol, 2‐aminoethanol and acryloyl chloride, in order to obtain a new polymerisable fluorescent dye. The synthesised dyes were characterised by differential scanning calorimetry, absorption spectroscopy (Fourier Transform–infrared, proton and carbon nuclear magnetic resonance, ultraviolet–visible spectroscopy) and fluorimetry. Molar extinction coefficients and wavelength maxima were obtained by examining the dye solution in ethanol. The solvatochromic effects of the prepared dyes have also been investigated. Finally, the dye was copolymerised with methyl methacrylate and an intrinsically coloured copolymer was obtained. The photophysical characteristics of the obtained copolymer have also been considered. It is assumed that 99% of the copolymerised dye is chemically bonded to polymer chains. The fluorescent characteristics of the copolymer in the solid state were determined by fluorometer and it was found that it has relatively high fluorescent intensity. The physical properties of the synthesised copolymer have been evaluated by differential scanning calorimetry and gel permeation chromatography.     

Novel anti‐bacterial acid dyes derived from naphthalimide: synthesis,characterisation and evaluation of their technical properties on nylon 6

As an attempt to combine the dyeing and functional finishing steps into one process, two novel anti‐bacterial monoazo acid dyes based on N‐ester‐1,8‐naphthalimide were synthesised. To do this, 4‐amino‐N‐ethyl glycinate‐1,8‐naphthalimide was prepared, diazotised and then coupled to thiosalicylic acid or salicylic acid to produce anti‐bacterial dyes. The synthesised dyes were purified and then fully characterised using Fourier Transform–infrared spectrometry, proton nuclear magnetic resonance spectroscopy and melting point analysis. Dispersion of the dyes was prepared in water and applied to nylon 6 fabrics. The novel dyes offered good build‐up properties on the substrate. The anti‐bacterial efficacy of the synthesised dyes was assessed, with the dyes showing activity against both Gram‐positive and Gram‐negative bacteria.     

Synthesis,stability and printing properties of a novel 2‐sulphophenoxy‐4‐chloro‐s‐triazine reactive dye for ink‐jet printing of wool

We report here the synthesis and characterisation of a new medium‐reactivity reactive dye containing 2‐sulphophenoxy‐4‐chloro‐s‐triazine, having enhanced the activity of the chlorine atom for further substitution by the functional groups carried by wool fibre. In addition, a dichloro‐s‐triazine dye was also synthesised for the purpose of comparison. The progress of synthesis reactions and purity of the dyes were determined using capillary electrophoresis and thin layer chromatography. The molecular structure and the chemical compositions of the synthesised dyes were confirmed using Fourier Transform–infrared spectral data and elemental analyses. The inks containing the synthesised dyes were formulated and ink‐jet‐printed onto wool fabrics and then the printed fabrics were steamed at 102°C. Compared with the dichloro‐s‐triazine dye, superior performance in terms of ink stability, K/S and dye fixation was observed for the new 2‐sulphophenoxy‐4‐chloro‐s‐triazine dye. In addition, the light fastness of the fabric printed with the inks containing the new dye was 0.5‐grade greater than that of the fabric printed with the inks containing the dichloro‐s‐triazine dye, and no changes in shade and staining were observed following wash fastness tests of the fabrics printed with the inks containing the new dye.     

Synthesis,spectral properties and dyeing on polyester of monoazo dyes from indol‐2‐one derivatives

Three series of phenylazo disperse dyes were prepared by coupling diazotised 4‐aniline dyes with 5‐indol‐2‐one dyes. The structures of these dyes were determined by proton nuclear magnetic resonance, Fourier Transform–infrared and elemental analysis. The effects of solvent on the ultraviolet–visible absorption spectra of these dyes were studied. The dyes displayed a λ_max shift of between 399 and 438 nm. The dyes were finally applied in the dyeing of polyester fibres in order to investigate their colour range and dyeing properties. Most of the dyes displayed high rubbing fastness and good washing and sublimation fastnesses on polyester fibres.     

Synthesis and application of KM‐type reactive dyes containing 2‐ethoxy‐4‐chloro‐s‐triazine

A new kind of hetero‐bifunctional reactive dye containing 2‐ethoxy‐4‐chloro‐s‐triazine, with better activity matching with β‐hydroxyethyl sulphone sulphate at a low fixation temperature, was successfully synthesised and characterised. An ethoxy group was designed to be introduced into triazine to increase the substantivity and the reactivity of the dyes. Thereby, the fixation of mono‐s‐chlorotriazine/hydroxyethyl sulphone sulphate (KM‐type) bifunctional reactive dyes on cotton was improved, and dyeing under mild conditions with high fixation was realised. Nineteen dyes with orange, red and blue colours were synthesised and characterised by UV‐Vis and infrared spectroscopy and mass spectrometry. Synthesised dyes were dyed at 60, 75 and 90°C, respectively. Exhaustion and reactivity for all of the ethoxy‐containing KM‐type dyes was over 90% at the optimal temperature, and fixation was over 87%, which was higher than the ethoxy‐free comparative dyes. The optimal fixation temperature of ethoxy‐containing dyes was initially reduced to 75°C, and then to 60°C. Compared with comparative dyes, the wash fastness and light fastness were basically unchanged, and the wet rub fastness of the H‐acid series was reduced by one grade.     

Aryl and heteroaryl azo dyes derived from 6, 8‐dichloro‐4‐hydroxyquinolin‐2 (1H)‐one: synthesis,characterisation, solvatochromism and spectroscopic properties

In this research study, 6, 8‐dichloro‐4‐hydroxyquinolin‐2(1H)‐one was prepared by the thermal cyclocondensation of 2‐(2, 4‐dichlorophenylcarbamoyl) acetic acid or N, N?‐bis(2,4‐dichlorophenyl)malonamide at 140‐150°C in polyphosphoric acid, resulting in a yield of 48%. This compound was then coupled with a series of diazonium salts derived from aromatic and heteroaromatic amines for synthesis of the corresponding azo dyes. The structures of the compounds were confirmed using elemental analysis as well as ultraviolet‐visible, Fourier Transform‐infrared and proton nuclear magnetic resonance spectroscopy. The effects of organic solvents with different polarities, pH values and substituents of the diazotising components on the maximum absorption wavelength of the colorants were discussed and evaluated in detail. The acidity constants (pK_a) of the dyes were also determined using the spectrophotometric method in an ethanol‐water mixture (80:20, v/v) at 20‐23°C.     

Broadband luminescence and emission enhancement

Three novel quinoline– and fluorene–coumarin hybrids were prepared and characterised by Fourier Transform–infrared spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy, mass spectrometry, elemental analysis and ultraviolet–visible spectrophotometry. Their photoluminescence properties were investigated. All of these hybrid molecules exhibited a broadband emission from ca. 450 to 800 nm when excited by a 325 nm helium–cadmium laser at room temperature. Importantly, the fluorene–coumarin hybrid shows a very bright red emission at ca. 650 nm and displays up to a 10‐fold increase in fluorescence emission intensity, as compared with the other samples. The experimental results confirm that remarkable enhancements in the fluorescence emission intensity can be obtained by introducing a fluorene group into the azo‐bridged coumarin‐based π‐conjugated framework. The geometry structures and frontier orbitals are calculated by the ab initio Hartree–Fock method.     

Synthesis and fluorescence properties of novel benzoxazole‐ and chromone‐functionalised bis(arylvinylene)imidazoles

Novel benzoxazole‐ and chromone‐functionalised bis(arylvinylene)imidazoles were synthesised and characterised by proton nuclear magnetic resonance, Fourier Transform–infrared, mass spectrometry and elemental analyses. These dyes were found to exhibit two quite different types of fluorescence behaviour in the alkali examined; i.e. fluorescence quenching for the benzoxazole–imidazole hybrids and fluorescence enhancement for the chromone–imidazole hybrids. The benzoxazole‐based imidazoles emit intense green fluorescence, but the fluorescence is remarkably quenched upon addition of alkali. Such a process can be reversibly controlled by simple deprotonation/protonation of the imidazole group; thus, they exhibit efficient fluorescence on/off switchable behaviour. In contrast, significant fluorescence enhancement is observed for the chromone–imidazole hybrids in the presence of alkali. Without alkali, these imidazole dyes are very weakly fluorescent, whereas the addition of alkali leads to an appearance of strong blue fluorescence and a dramatic increase of emission intensity.     

Efficient adsorption of dyes from aqueous solution by poly(vinyl alcohol‐co‐ethylene) nanofibre membranes modified with β‐cyclodextrin

In this paper, highly absorbent poly(vinyl alcohol‐co‐ethylene) nanofibre membranes modified by β‐cyclodextrin were prepared to adsorb dyestuff from water, and 1,2,3,4‐butanetetra carboxylic acid was used as a crosslinking agent, which greatly enhanced the adsorption capacity of the modified membranes. Field emission scanning electron microscopy and Fourier Transform–infrared spectroscopy were used to characterise the surface morphology and chemical structures of the membranes. Methylene Blue (MB) was used as the main adsorbed dye. The effect of pH value and concentration of the MB solution were also investigated, and equilibrium adsorption reached 139.2 mg/g when the pH value was 10.0. The adsorption process fitted well with the Langmuir adsorption isotherm model and was in accord with the pseudo‐second‐order kinetic model. Moreover, the modified membranes proved to have selective adsorption, especially for some cationic dyes other than MB, and had the potential to be recycled multiple times.     

Synthesis and absorption spectra of some novel hetaryldisazocalix[4]arene derivatives

In this study, a convenient method for the synthesis of thirteen novel disazo dyes containing 25,26,27‐tribenzoyloxy‐28‐hydroxycalix[4]arene have been described. 5,11,17,23‐Tetra‐tert‐butyl‐25,26,27,28‐tetrahydroxycalix[4]arene, 25,26,27,28‐tetrahydroxycalix[4]arene and 25,26,27‐tribenzoyloxy‐28‐hydroxycalix[4]arene were synthesised based on previously published literature. 2‐Arylhdrazone‐3‐ketiminobutyronitriles were synthesised and reacted with hydrazine hydrate to afford the corresponding 5‐amino‐4‐arylazo‐3‐methyl‐1H‐pyrazoles. Thirteen novel hetaryldisazocalix[4]arene derivatives were achieved by diazotisation of 5‐amino‐4‐arylazo‐3‐methyl‐1H‐pyrazoles using nitrosylsulphuric acid, coupled with 25,26,27‐tribenzoyloxy‐28‐hydroxycalix[4]arene. The obtained hetaryldisazocalix[4]arene dyes were characterised based on Fourier Transform–infrared, proton nuclear magnetic resonance and mass spectroscopic techniques, as well as elemental analysis. The solvatochromic behaviour of these dyes in various solvents was examined. Acid‐base effects on the visible absorption maxima of the dyes were also reported.     

Dyeing properties of novel electrolyte‐free reactive dyes on cotton fibre

A series of electrolyte‐free reactive dyes containing two quaternary ammonium salt groups as soluble moieties and one epoxy structure as the reactive group have been synthesised. The structures of the synthesised dyes were confirmed by Fourier Transform–infrared, proton nuclear magnetic resonance and elemental analysis, and their dyeing properties on cotton were studied using an electrolyte‐free dyeing process. The results indicate that electrolyte‐free reactive dyes with these structures give a high exhaustion rate, a high fixation rate and good build‐up properties on cotton. Fastness properties were, in general, also very good. The optimal dyeing process of these electrolyte‐free dyes for cotton fibre was 60 °C with 20 g/l sodium carbonate.     

Synthesis and spectroscopic investigation of cationic donor‐(π‐bridge)‐acceptor dye, 4‐[N‐(5,6,7,8‐tetrahydroisoquinolinium‐5‐ylidene)methyl]‐N,N‐dialkylaniline iodide

The synthesis and fundamental spectroscopic properties of eight hemicyanine (HC) dyes are presented. The dyes were prepared by the condensation of N‐methyl‐5,6,7,8‐tetrahydroisoquinolinium iodide with p‐(N,N‐dialkylamino)benzaldehydes. The compounds were characterised by nuclear magnetic resonance spectroscopy and their purity was checked with the use of thin‐layer chromatography. The spectroscopic properties of the dyes were determined in three organic solvents. The electronic absorption spectra of the dyes demonstrate moderate sensitivity to the nature of the substituent present in the aromatic ring and low solvent polarity dependence. In contrast to this, the positions of fluorescence bands are affected by the structure of an electron donor and solvent polarity. The 4‐[N‐(5,6,7,8‐tetrahydroisoquinolinium‐5‐ylidene)methyl]‐N,N‐dialkylaniline iodides were applied as fluorescent probes for the monitoring of the progress of free radical polymerisation. The study on the changes in the fluorescence intensity and spectroscopic shifts of the dyes was carried out during thermally initiated polymeriszation of methyl methacrylate. The purpose of these studies was to find a relationship between the changes in the shape and intensity of probe fluorescence and the degree of monomer conversion into polymer.     

Synthesis,spectral and dyeing properties of phenylazopyrazolone‐containing acylamide disperse dyes designed for poly(lactic acid)

A series of phenylazopyrazolone disperse dyes containing an acylamide moiety were synthesised from carboxyl‐containing acid dyes via chlorination and amidation with different sorts of amines. The structures of these new dyes were confirmed by Fourier Transform–infrared, proton nuclear magnetic resonance, mass spectroscopy and elemental analysis. Their solvatochromic properties in different solvents were also investigated and the absorbance spectra of the acylamide dyes in solution exhibited a red shift when dissolved in dimethylformamide, compared with acetone. Their dyeing behaviour, including dye sorption, colour build‐up and colour fastness properties on poly(lactic acid) fibres, was also determined, whereupon it was found that the tertiary acylamide dyes simultaneously exhibited high dye sorption and satisfactory colour build‐up and fastness properties on the poly(lactic acid) fabric.     

Synthesis and characterization of a new conducting polymer based on 4‐(2,5‐di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl)‐phthalonitrile

A new conducting polymer was synthesized by electrochemical polymerization of 4‐(2,5‐di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl)‐phthalonitrile (SNS‐PN). Electrochemical polymerization of SNS‐PN was performed in acetonitrile/0.2M LiClO₄ solvent/electrolyte couple. Characterizations of the resulting polymer P(SNS‐PN) were carried out by cyclic voltammetry, UV–vis, and Fourier transform infrared (FTIR) spectroscopic techniques. Spectroelectrochemical studies revealed that P(SNS‐PN) has an electronic band gap of 2.45 eV and exhibits electrochromic behavior. The switching ability of polymer was also monitored and the percentage transmittance change (ΔT%) was found as 24%. It is also found that P(SNS‐PN) is fluorescent and its fluorescence intensity enhances in the presence of cations. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis,spectral properties and application of novel disazo disperse dyes derived from polyester waste

Terephthalic dihydrazide was obtained through aminolytic depolymerisation of polyester bottle waste by using hydrazine hydrate. It was further reacted with 4‐aminobenzoic acid in the presence of polyphosphoric acid to obtain a cyclic compound, 4,4′‐[5,5′‐(1,4)‐phenylene)bis(1,3,4‐oxadiazole‐5,2‐diyl)dianiline, having a heterocyclic moiety. Diazotisation of this compound followed by coupling with various N,N‐disubstituted anilines afford a series of novel disazo disperse dyes. The structures of these synthesised dyes were confirmed by elemental analysis and Fourier Transform–infrared, proton nuclear magnetic resonance and mass spectroscopy. Ultraviolet–visible spectra of these azo dyes in different polar solvents showed considerable variation in the wavelength of maximum absorbance (λ_max). Application of these dyes on polyester and nylon fabrics using high‐temperature dyeing methods gave brilliant yellowish red hues with fair to moderate light fastness and very good to excellent wash fastness and sublimation fastness.     

Electropolymerization of a new 4‐(2,5‐Di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl)‐tetra substituted nickel phthalocyanine derivative

A new tetrakis 4‐(2,5‐di‐2‐thiophen‐2‐yl‐pyrrol‐1‐yl) substituted nickel phthalocyanine (NiPc‐SNS) was synthesized and characterized by elemental analysis, Fourier Transform Infrared (FT‐IR), and UV–vis spectroscopies. The electrochemical polymerization of this newly synthesized NiPc‐SNS was performed in dichloromethane (DCM)/tetrabutylammonium perchlorate (TBAP) solvent/electrolyte couple. An insoluble film was deposited on the electrode surface, both during repetitive cycling and constant potential electrolysis at 0.85 V. Resulting polymer film, P(NiPc‐SNS), was characterized utilizing UV–vis and FT‐IR spectroscopic techniques and its electrochemical behavior was investigated via cyclic voltammetry (CV). Spectroelectrochemical behavior of the polymer film on indium tin oxide (ITO) working electrode was investigated by recording the electronic absorption spectra, in situ, in monomer‐free electrolytic solution at different potentials and it is found that the P(NiPc‐SNS) film can be reversibly cycled between 0.0 and 1.1 V and exhibits electrochromic behavior; dark olive green in the neutral and dark blue in the oxidized states with a switching time of 1.98 s. Furthermore, the band gap of P(NiPc‐SNS) was calculated as 2.27 eV from the onset of π–π* transition of the conjugated backbone. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterisation of benzothiazole‐based solid‐state fluorescent azo dyes

Novel solid‐state fluorescent azo dyes containing a 2‐[4‐(dimethylamino)phenyl]benzo[d]thiazol‐6‐amine as the electron donor group were synthesised. These dyes showed a molar extinction coefficient in the range of 20 000–30 000 l/mol/cm. These compounds were characterised by strong solid‐state fluorescence under long ultraviolet light (365 nm). Absorption and fluorescence spectra revealed that electron coupling originating from broad π‐electron delocalisation and the keto–enol form is responsible for the large Stokes shift. These dyes were readily soluble in common solvents such as dichloromethane, chloroform, dimethyl formamide , tetrahydrofuran and dimethyl sulphoxide and were characterised by means of elemental analysis, proton nuclear magnetic resonance and mass spectrometry. Thermogravimetric analysis of solid‐state fluorescent dyes show thermal stability up to 270 °C and can therefore be used for polymer application. The coloristic properties of these dyes were evaluated on polyester by the disperse dyeing method.     

Green synthesis of reactive dye for ink‐jet printing

Chloropyrimidine‐based reactive dyes are reported as well suited to textile printing; however, nucleophilic aromatic substitution of chloropyrimidines with amino‐containing chromophores is slow and often suffers from poor yields. In this study, a novel and simple method was developed for the synthesis of chloropyrimidine‐based reactive dye under microwave irradiation. In addition, the dye was also synthesised by conventional heating for comparison, which took both the reaction time and yield into account. The progress of the synthesis reactions concerned were monitored using capillary electrophoresis and the purity of the dye obtained was assessed by thin‐layer chromatography. The structure of the synthesised trichloropyrimidine dye was confirmed by Fourier Transform–infrared spectroscopy and elemental analysis. It was found that the reaction rate of the nucleophilic aromatic substitution carried out under microwave irradiation was 4‐fold faster than that carried out under conventional heating, although the enhancement in product yield was modest. These results suggest that microwave irradiation is an effective technique for the synthesis of chloropyrimidine‐based reactive dyes. The synthesised chloropyrimidine dye was formulated into an ink and applied onto a wool fabric by ink‐jet printing. The printed fabrics were steamed at 102°C for 5‐25 minutes at 5‐minute intervals. Good K/S and rate of dye fixation were obtained, both of which improved with increasing steaming time. The prints obtained exhibited reasonably good light and wash fastness properties.     

A new dye‐modified poly(ethylene oxide)–poly(propylene oxide) polymer used as a dispersant for CI Disperse Red 60

A new dye‐modified poly(ethylene oxide)–poly(propylene oxide) polymer, in which the dye molecule (CI Disperse Red 60) is bonded onto polyether monoamine via a triazine ring, was synthesised for the preparation of dye aqueous dispersions and was characterised by Fourier Transform‐infrared spectroscopy, ¹H nuclear magnetic resonance spectroscopy and elemental analysis. This polymer exhibits unique dispersing performance for CI Disperse Red 60. The mechanism behind the improved performance is briefly discussed with the help of adsorption isotherms. The results indicated that the hydrophobic dye group of this polymer can strongly adsorb onto the dye particle surface through π–π interaction while its long hydrophilic poly(ethylene oxide) chains allow the formation of a thick layer around the dye particles. It was speculated that the adsorbed polymer molecule on the dye surface would form a brush‐like monolayer conformation. The dyeing performance of the prepared dye dispersions on polyester fabrics was also investigated. It was found that this polymer can effectively increase the apparent solubility of disperse dye. The dyed fabrics showed very good to excellent fastness to washing and rubbing, while the dyeing effluent was colourless.     

Homogeneous graft copolymerization of chitosan with butyl acrylate by γ‐irradiation via a 6‐O‐maleoyl‐N‐phthaloyl‐chitosan intermediate

The graft copolymerization of butyl acrylate (BA) onto chitosan was tried via a new protection‐graft‐deprotection procedure. About 6‐O‐maleoyl‐N‐phthaloyl‐chitosan was synthesized and characterized by Fourier transform infrared spectra analysis (FT‐IR) and ¹H‐NMR. Because the intermediate 6‐O‐maleoyl‐N‐phthaloyl‐chitosan was soluble in organic solvents, the graft copolymerization was carried out in a homogeneous system. Grafting was initiated by γ‐irradiation. The graft extent was dependent on the irradiation dose and the concentration of BA monomer, and copolymers with grafting above 100% were readily prepared. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 489–493, 2006