Dyeing of nylon 6 fabric with a bifunctional sulphatoethylsulphone reactive disperse dye

A bifunctional reactive disperse dye containing two temporarily anionic sulphatoethylsulphone groups was synthesised and applied to nylon 6 fabric by exhaust dyeing at a variety of pH levels and temperatures. A monofunctional reactive disperse dye containing one temporarily anionic sulphatoethylsulphone group was also synthesised, and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and total fixation yield under alkaline conditions. The results also indicate that the introduction of two temporarily anionic sulphatoethylsulphone groups of the bifunctional dye gave an enhancement in dyeing performance compared with that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Dyeing of nylon 6 fabric with a new bifunctional vinyl sulphone reactive disperse dye

A new bifunctional reactive disperse dye containing a temporarily anionic sulphatoethylsulphone and a nonionic disulphide bis(ethylsulphone) groups was synthesised and applied to nylon 6 fabric by the exhaust dyeing at a variety of pH and temperature conditions. A monofunctional reactive disperse dye containing only nonionic disulphide bis(ethylsulphone) group was also synthesised and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and fixation values at pH 6 and 120 °C. The results also indicate that the combination of temporarily anionic and nonionic reactive groups of the bifunctional dye provided great enhancement in dyeing performance compared to that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Dyeing of nylon 6 and silk fabrics with a model disulphide bis(ethylsulphone) reactive disperse dye

The synthesis of a new reactive disperse dye containing the disulphide bis(ethylsulphone) group is described. The dye has been applied to nylon 6 and silk fabrics at a variety of pH and temperature conditions. Optimum dye exhaustion and fixation were achieved at pH 8 and 130 °C. The results of dyeings on both substrates indicate that the model disulphide bis(ethylsulphone) reactive disperse dye shows a higher degree of exhaustion and fixation on silk than on nylon 6. The fastness and levelling properties on both fabrics were good.     

The tracer diffusion of dye anions in nylon 6 film

The tracer diffusion coefficients of three S-35-labeled dyes in nylon 6 film have been determined. The diffusion coefficients show marked concentration dependence, but this takes a form different from that shown by chloride ions in a related study. It is not possible to explain the data on the basis of electrostatic factors as in earlier work in which diffusion was accompanied by a free-energy change. A diffusional interaction between dye molecules is postulated which takes the form of a free-volume saturation effect leading to an upper limiting diffusion coefficient at adsorption levels which depend upon the polymer order and the characteristics of the diffusing ion.     

Diffusion of dye mixtures in nylon 6. Binary mixtures of disperse dyes

The diffusion of binary dye mixtures of markedly different chemical constitutions (4-nitro-4′-aminoazobenzene and 1-amino-4-hydroxyanthraquinone) and of similar ones (1-amino-4-hydroxyanthraquinone and 1,4-dihydroxyanthraquinone) into nylon 6 film was examined. Apparent diffusion coefficients of dyes in the mixture within a single dyeing were determined by the film roll method at 60°, 70°, 80°, and 90°C. Diffusion coefficients of individual dyes used in a mixture of chemically dissimilar dyes are found to change little in comparison with single dyeings, while diffusion coefficients of dyes of similar structures are decreased appreciably. It is suggested that the latter effect is due to the interaction between two dyes in the fiber substrate.     

Temperature dependence of diffusion of a disperse dye in the multiple layers of nylon fabric

The apparent diffusion coefficients of a disperse dye in the multiple layers of nylon fabric at 45-75°C are determined as the dyeing model of the textile assembly. The modified pore model is introduced to explain the diffusion behavior in the multiple fabric. The Arrhenius plot of the diffusion coefficient of dye in the spaces or pores of nylon fabric gave a straight line and the activation energy of diffusion was about 9.4 kcal/mol. The temperature dependence of the dye diffusivity in polymer matrix was quantitatively described by a WLF-type relation, where a_T is a shift factor of diffusion and T_s is the reference temperature.     

The dyeing of nylon with a microencapsulated disperse dye

Melamine resin microcapsules containing CI Disperse Blue 56 were prepared by in situ polymerisation. The microcapsules were characterised by their thermal properties and morphology, such as particle size and particle size distribution. The dyeing behaviour of the microcapsules on nylon 6.6 was evaluated. The microencapsulated dye exhibited good build-up, levelness and fastness properties. It has been demonstrated that microencapsulated disperse dye can be used to replace commercial disperse dyes in dyeing polyamide fabric without dyeing additives, and the resulting effluent can be easily recycled after filtration.     

Solubility of a reactive disperse dye in supercritical carbon dioxide

The solubility of a reactive disperse dye, which was modified from CI Disperse Red 17 with a derivative of 1,3,5‐trichloro‐2,4,6‐triazine as the reactive group, was investigated in supercritical carbon dioxide fluid by employing a batch system equipped with an online spectrophotometer. The investigations were carried out at pressures of 7.5–25.0 MPa, temperatures of 333.15–413.15 K and an equilibrium contact time of 120 min. As revealed from the experimental results, the solubility of the reactive disperse dye increased with pressure in different isotherms, and decreased with temperature. Furthermore, the experimental solubility data were correlated successfully with semi‐empirical models – Chrastil and Del Valle–Aguilera equations, respectively – at various temperatures and pressures.     

Decolorization of disperse and reactive dye solutions using ferric chloride

The composition of wastewater from dyeing and textile processes is highly variable depending on the dyestuff type; typically it has a high chemical oxygen demand. This study examined the decolorization of some of the most commonly used disperse and reactive dyestuffs by destabilization using ferric chloride as a coagulant. Dye removal, distributions of zeta potential, concentration of suspended solids, changes of the SCOD/TCOD ratio and distributions of SV and SVI values were investigated in this work. Compared to reactive dyes, disperse dyes have lower solubility, higher suspended solids concentrations and lower SCOD/TCOD ratios. It was concluded that disperse dye solutions are more easily decolorized by chemical coagulation than reactive dye solutions.     

Imparting insect repellency to nylon 6 fibers by means of a novel MCT reactive dye

Insect repellency of fiber is a property which makes the fiber to be of interest in the field of military and health. The insect‐repellent substrate could be prepared using either functional finishing or applying an insect‐repellent dye. In this article, insect‐repellent nylon 6 is obtained using a novel insect‐repellent reactive dye containing N,N‐diethyl‐m‐toluamide. To do this, N,N‐diethyl‐m‐toluamide (DEET) was first nitrated at the p‐position relative to amide functionality. The nitrated product was reduced in the presence of C₂H₅OH, SnCl₂, and HCl. The produced amine was then condensed with 2,4,6‐trichloro‐1,3,5‐triazine (cyanuric chloride) as a reactive group in below 5°C. The resultant adduct was finally reacted with an amino group present in 6‐amino‐1‐hydroxy naphthalene‐3‐sulfonic acid (J‐acid) to produce 7‐(4‐chloro‐6‐(4‐(diethylcarbamoyl)‐2‐methylphenylamino)‐1,3,5‐triazin‐2‐ylamino)‐4‐hydroxynaphthalene‐2‐sulfonic acid. To synthesis azo dye, sulfanilic acid was diazotized using HCl and NaNO₂ and then coupled to the above prepared component to produce insect‐repellent reactive dye. An analog dye was prepared via the same route without insect‐repellent group making stage. The chemical structures of the novel dyes were characterized using FTIR and ¹H‐NMR spectroscopy. The spectroscopic properties of the dyes were determined in terms of λ_max and ε_max in aqueous solution. The novel dyes were then reacted with nylon 6 and bonded to it covalently to provide permanent insect‐repellent substrate. The insect‐repellent efficacy of the reacted nylon 6 was studied using standard methods for Anophele mosquito repellent. The insect‐repellent dye reacted nylon 6 showed insect‐repellent activity. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Concentration-dependent diffusion of dye in reactive dyeing systems

The cure of a tetrafunctional epoxy resin (largely tetraglycidyldiaminodiphenylmethane, TGDDM), cross-linked with diaminodiphenylsulphone (DDS) and boron trifluoride/ethylamine (BF₃EA) catalyst, is affected in a complex fashion by the presence of an oxidized carbon fiber surface. If the fiber is aged in a humid environment (25°C, 95% humidity) before coating with the matrix, the affinity of the oxidized fiber surface for water leads to destruction of the catalyst and retardation of the cure. This retardation is noticeable at lower humidities if the polymer content of the composite is reduced to > 20%. For oxidized fibers that are stored under ambient conditions (40% humidity), the retarding effect of water is overwhelmed by the catalytic effect of the acidic fiber surface. This activates the latent catalyst, increasing the rate of epoxy consumption and the proportion of the epoxy–epoxy reaction relative to the epoxy–amine reaction. For the low-humidity case, even though the rate of chemical reaction is increased, vitrification of the matrix is retarded, implying that there is less cross-linking and more extended epoxy–epoxy sequences in the network. The proposed chemical changes in epoxy/carbon fiber composites were confirmed by analysis of model reactions in solution. © 1992 John Wiley & Sons, Inc.     

The influence of polymer and dye characteristics on diffusion in nylon 66

A study has been carried out of the relationship between polymer orientation and dyeing behavior using a specially prepared range of nylon 66 samples varying only in orientation and five dyes normally showing varying degrees of sensitivity to physical variations in nylon. Integral diffusion coefficients have been calculated using Crank's finite dyebath equation from appropriate rate of dyeing data. Evidence has been produced which suggests that except with dyes of low molecular weight, i.e., dyes insensitive to physical variations in the nylon, a diffusional interaction between diffusing dye molecules exists which leads to a variation in the concentration dependence of the diffusion coefficient with fiber orientation. The length of the diffusing dye ion has been shown to be of decisive importance in this interaction.     

Hydrolysis of a disperse reactive dye for application to wool fibres

The synthesis of a reactive dye in the anhydride form is described, and its kinetics of hydrolysis investigated at various pH values. Two different hydrolysis products were identified. The experimental rate constants were determined by nonlinear approximation. It was found that the experimental rate constant depends on pH, with the maximum between pH 5 and 6. The best wool dyeing conditions were obtained by dyeing for 60 min at 100d?C and pH 7.     

Laser scanning confocal microscope characterization of dye diffusion in nylon 6 fibers treated with atmospheric pressure plasmas

The effect of atmospheric pressure plasma treatment on wettability and dyeability of nylon 6 fibers is investigated. The plasma treatments resulted in an average of 10°–20° decrease in the advancing contact angle and 20°–30° decrease in the receding contact angle. An increased dye diffusion rate of nylon 6 fibers was observed using laser scanning confocal microscope (LSCM). Scanning electron microscope confirmed that the fiber surfaces were roughened, and X‐ray photoelectron spectroscopy showed that the polar groups on the fiber surfaces increased after the plasma treatments. As the plasma treatment time increased, a greater degree of etching was achieved and more polar groups such as hydroxyl and carboxyl groups produced on the surfaces of the nylon 6 fibers, leading to a better wettability and thus a better dyeability of the fiber. This study proved that LSCM may be effectively used in detecting the change of dye diffusion rate in nylon fibers treated with plasmas and the mounting medium should have a close refractive index as the fiber to avoid distortion of the fiber cross section image. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Transport of acid dye in nylon and concentration dependence of the diffusion coefficient

The dyeing kinetics of an acid dye (C. I. Acid Blue 40) in a nylon 6 film were investigated using partition-cell and film-roll methods at 80°C and pHs 2.3 and 3.05. The concentration dependence of diffusion coefficient of the dye in the nylon substrate measured by both methods was interpreted in terms of parallel diffusion with biomodel sorption of the Nernst and Langmuir modes. As the concentration of dye increases, the transport of dye inside the nylon film becomes dominated by pore diffusion and surface diffusion of sorbed Nernst populations.     

Synthesis of an anthraquinonoid disperse reactive dye based on a ligand-free Ullmann reaction

A new anthraquinonoid disperse reactive dye containing a dichlorotriazine reactive group was successfully synthesised on the basis of the Ullmann reaction in a ligand-free system by employing a copper(i ) iodide as catalyst, in combination with a subsequent condensation reaction. The parameters of the cross-coupling reaction between 1-chloroanthraquinone and 2,5-diaminotoluene sulphate were investigated and optimised, such as the molar ratio of the reactants, the dosage of potassium carbonate and copper(i ) iodide, the reaction temperature, and the reaction time. The results demonstrate that the dosage of potassium carbonate and the reaction time had significant impacts on the yield of the dye precursor, and an optimum synthesis process was also recommended. Moreover, the achieved dye was successfully characterised and confirmed from chemical structure and colour characteristics by employing Fourier transform infrared analysis, nuclear magnetic resonance spectroscopy, UV-vis absorption spectroscopy, elemental analysis, and liquid chromatography–mass spectrometry (LC-MS). Furthermore, a successful application of the obtained dye was achieved, with satisfactory coloration properties on silk and wool.     

Fading characteristics of a disperse dye on cellulose triacetate, polyester and nylon under monochromatic light radiation

Light fastness of CI Disperse Blue 165 dye on cellulose triacetate, polyester and nylon fabric substrates exposed to monochromatic light was examined on a radiant energy basis. The action spectra indicated a strong effect on the substrate-fading characteristics: nylon exhibited poorer light fastness in the visible and ultraviolet light range than polyester and cellulose triacetate. Two specific fading peaks were found for the nylon substrate, which were different to those found for the polyester and cellulose substrates. It was shown that polyester exhibited the best light fastness properties overall. The colour changes in the fading process suggested that the fading products of the dye on nylon (where reduction occurred) were different from those on the polyester and cellulose triacetate substrates (where oxidation occurred).     

Dyeing of nylon with reactive dyes. Part 1. The effect of changes in dye structure on the dyeing of nylon with reactive dyes

The dyeing behaviour of seven red commercial cellulosic reactive dyes, all based on the same chromophore and possessing one or more reactive group, and one to three chromophore units, were evaluated on nylon. Fixation levels appeared to be independent of the number of either reactive groups or chromophore units. Also, the degree of sulphonation, per se, appeared to have little effect on fixation, whereas the type of reactive group was important. The major determinant of dye fixation appeared to be associated with the shape of the molecule and the type, not the number, of reactive groups.     

Non-isothermal crystallization kinetics of reactive microgel/nylon 6 blends☆

The non-isothermal crystal ization kinetics of reactive microgel/nylon 6 blends was investigated by differential scanning calorimetry (DSC). The Mo equation was employed to analyze the non-isothermal crystallization data. The crystallization activation energies were also evaluated by the Kissinger method. The results show that the crystallization onset temperature (Tonset) and crystallization peak temperature (Tp) decrease with the increase of the content of reactive microgel, whileΔT (Tonset–Tp), the crystallization half-time (t1/2) and the crystal ization enthalpy (ΔHc) increase. The required cooling rates of blends are higher than that of neat nylon 6 in order to achieve the same relative crystallinity in a unit of time. The crystallization activation energies of the reactive microgel/nylon 6 blends are greater than those of the neat nylon 6. When the content of reactive microgel is 30%, the relative crystallinity (Xt) reaches the maximum.