Adsorption and fixation of a reactive dye on cotton in non-aqueous systems

The dyeability of a reactive dye, CI Reactive Red 2, on cotton in non-aqueous media has been investigated using a reverse-micellar solution. Reverse micelles comprising Aerosol-OT/iso-octane were taken as a model for dyeing in non-aqueous systems. The reactive dye was satisfactorily solubilised in the interior of the reverse micelle. Exhaustion of the reactive dye on cotton from the reverse micellar solution was excellent even in the absence of a dyeing auxiliary. Effective fixation was achieved by the use of a separate reverse-micellar solution containing a suitable alkali. It has also been shown that fixation can be successfully achieved using an alternative thermal process without the need for alkali.     

Triazinylamino-alkylphosphonate reactive dyes for cellulosic fibres

A bifunctional reactive bis-phosphonoalkylaminotriazine dye was synthesised by condensing 2 mol of aminoethylphosphonic acid with the commercially available bis-monochloro- s -triazinyl dye, CI Reactive Red 120. A similar but much lower molecular weight dye was prepared by condensing the commercially available dichloro- s -triazine dye, Procion Red MX 8B, with aminomethylphosphonate. A model aryl-phosphonate dye was also prepared by diazotising m -aminobenzene-phosphonic acid and coupling the diazonium salt to R-salt. These dyes were isolated as their free acids and then converted to their ammonium salts. Pad liquors containing dye, cyanamide and ammonium dihydrogen phosphate were applied to cotton fabric. In the case of the bis-phosphonoethylamino- s -triazine dye, very high dye–fibre fixation values (>90%) were achieved using a pad–batch–bake procedure; for the Procion T model dye, the comparative maximum fixation was only modest. In the absence of cyanamide, no fixation could be obtained for the arylphosphonate dye but both bis-phosphonoalkylaminotriazine dyes gave significant fixation.     

Foam properties and application in dyeing cotton fabrics with reactive dyes

The foam dyeing of cotton fabric with CI Reactive Red 120 has been studied as a low‐add‐on technology. The foamability of different types of foaming agent and the stability of foam stabilisers were compared. Factors influencing foam dyeing, including wet pick‐up, fixation agent, foam stabiliser, and blow ratio, were evaluated by colour strength and dye fixation rate. Wet pick‐up, fixation agent, and foam stabiliser were found to be the main factors in the foam dyeing process. The comparative build‐up properties, dyeing properties, and total consumption between foam dyeing and conventional dyeing were assessed. The results indicate that, in foam dyeing, the dyestuff has a better build‐up property, the dyed fabric has excellent wash and rub fastness, and large amounts of water and energy are saved. Moreover, foam dyeing requires smaller dosages of chemical agents and reduces the difficulty of effluent treatment.     

Synthesis of a di‐(p‐sulphophenoxy)‐s‐triazine reactive dye and its application in wool fabric ink‐jet printing

Reactive dyes based on p‐sulphophenoxy‐s‐triazines were synthesised, characterised and applied to wool fabric by ink‐jet printing. The extent of dye‐fibre covalent bonding (% fixation) was measured on prints produced using different development methods. The most promising method to obtain high dye‐fibre fixation values was to interleave the printed wool with a pre‐wetted cotton fabric and store for 3 h. Steam fixation was also investigated but gave lower fixation values. The degree of dye hydrolysis vs time in the ink formulation was evaluated because ink stability is critical in commercial operation; a reformulated ink based on a phosphate buffer was found to improve ink stability.     

One‐bath union dyeing of a modified wool/acrylic blend with acid and reactive dyes

Pretreated wool/acrylic fibre was obtained by a facile amidoximation process. Fibre characterisation (nitrogen content, tensile strength, shrinkage, infrared spectra and X‐ray diffraction) proved the success of the pretreatment. Union dyeing of wool/acrylic fabrics with acid and reactive dyes, namely CI Acid Red 40, CI Acid Blue 25, CI Reactive Red 194 and CI Reactive Blue 25, was obtained using a one‐bath dyeing process. Different factors that may affect the dyeability of the blend fibre, such as dyebath pH, liquor ratio, temperature, time and dye concentration, were evaluated with respect to the dye exhaustion, fixation, colour strength, levelling and fastness properties. Excellent to good fastness was obtained for all samples, irrespective of the dye used. The result of the investigation offers a new viable method for union dyeing of wool/acrylic fibres in a one‐dyebath process.     

Pretreatment of cotton with poly(vinylamine chloride) for salt-free dyeing with reactive dyes

Poly(vinylamine chloride) has been investigated as a pretreatment for the salt-free dyeing of cotton with reactive dyes. Dye fixation was found to be much higher than by conventional dyeing without pretreatment, even in the presence of a large amount of salt. The influence of pretreatment conditions on dye fixation, such as pad–bake variables and the concentration of poly(vinylamine chloride), has been studied. The dyeing behaviour of CI Reactive Red 2 on pretreated cotton was examined and found to follow a Langmuir-type adsorption curve. Dyed cotton pretreated with poly(vinylamine chloride) showed excellent wash fastness and good rub fastness. It is concluded that poly(vinylamine chloride) is effective as a pretreatment for salt-free dyeing with reactive dyes.     

Ultrasonic‐assisted dyeing: I. Nylon dyeability with reactive dyes

The use of ultrasonic power (38.5 KHz, 350 W) to assist the dyeability of nylon‐6 fibre with reactive dyes is reported. The effects of the different factors that may affect the dyeability of nylon‐6 fibre with Reactive Red 55 were simultaneously carried out under both ultrasonic power and conventional heating conditions. The colour strength values obtained for the dyed samples using ultrasonic power were higher than those obtained using conventional heating. Also, the effect of alkaline soaping treatment on dye fixation for the dyed fabrics with different reactive dyes, at both acidic and neutral pHs, is generally better with ultrasonic than with conventional heating. The overall results indicate that the enhancing effect is mainly attributed to the de‐aggregation of dye molecules, which leads to better dye diffusion and possible assistance for dye‐fibre covalent‐bond fixation. The results of wet fastness properties of the dyed fabrics reveal improvement using ultrasonic power dyeing relative to the conventional heating method. © 2003 Society of Chemical Industry     

Ink‐jet printing process for lyocell and cotton fibres. Part 2: The relationship of colour strength and dye fixation to ink penetration

The colour appearance on ink‐jet printed textiles is influenced by a range of factors, including the chemical and physical nature of the fibre, dye–fibre affinity, pretreatment and fabric structure. Regression analyses were conducted to study the correlation between colour strength, fixation and ink penetration obtained by ink‐jet printing lyocell fibres (standard Tencel and Tencel A100) and cotton with an ink based on a monofunctional reactive red dye. The fixation was highest on Tencel A100, followed by standard Tencel and then cotton, while colour strength was highest on standard Tencel followed by cotton and Tencel A100. A linear relationship between colour strength and ink penetration was found with cotton, indicating greater dependence of depth of shade on ink penetration than on standard Tencel and Tencel A100 fabrics, where the interrelationships were more complex, but of low statistical significance. A schematic representation is proposed illustrating the mechanism of ink penetration into pretreated fibres, which provides a reasonable interpretation of the events occurring as dye penetrates into and fixes onto the fibres.     

Technological evaluation of reactive cyclodextrin in cotton printing with reactive and natural dyes

The chemical modification of cotton fabric with reactive cyclodextrin (R‐CD) at different concentrations was carried out to enhance the printability of cotton fabric. The extent of the modification reaction was expressed as %N. Reactive and natural dyes were used to print cotton fabric before and after modification. Printing pastes were applied immediately after preparation or after 24 h of storage. Printing fixation was performed through either steaming or thermal treatment. The effect of the incorporation of R‐CD in the printing paste of unmodified cotton was also studied. The results reveal that the extent of the modification reaction increased with increasing R‐CD concentration and so did the color strength (K/S) of the printed sample regardless of the dye used. The results also revealed that K/S of the R‐CD modified cottons were higher than that of the corresponding unmodified samples regardless of the method of fixation or the time elapsed before printing. On the other hand, the incorporation of R‐CD in the printing pastes of reactive dyes, namely, Cibacron Brown 6R‐P or Remazol Brilliant Red GG, had adverse effects, most probability due to the (a) increasing viscosity of the paste and/or (b) interaction of the reactive dye with R‐CD hydroxyls. The opposite held true when a natural dye was used. Further, the incorporation of R‐CD in the printing pastes had no effect on the rheological type of the pastes or the on overall fastness properties of the prints. Nevertheless, such an incorporation of R‐CD was accompanied by a remarkable increase in the magnitude of the apparent viscosity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 338–347, 2006     

Dyeing of cotton with a bifunctional disulphide bis(ethylsulphone-sulphatoethylsulphone) disazo reactive dye

A new bifunctional disazo reactive dye of a temporarily high molecular structure based on a disulphide bis(ethylsulphone-sulphatoethylsulphone) reactive system was synthesised and applied to cotton fabric. This dye displayed good primary exhaustion under different neutral exhaustion conditions. The results assessed for the alkaline exhaust dyeing indicate that the disulphide bis(ethylsulphone-sulphatoethylsulphone) dye showed higher exhaustion and fixation values compared to those obtained with the commercial CI Reactive Black 5. The fastness properties of the disulphide dye were similar to those of the commercial dye. Received: 24 March 2005; Accepted: 15 June 2005.     

季铵型阳离子聚丙烯酰胺的无盐染色行为

以季铵型阳离子聚丙烯酰胺作为一种新的阳离子助剂对棉纤维进行处理,应用于活性染料无盐染色,对染色过程中染料与处理后棉纤维之间的吸附类型、吸附热力学及吸附动力学进行了研究。结果表明,无盐染色过程符合Langmuir吸附模型;吸附过程是放热自发进行的,低温有利于染料的吸附;吸附动力学符合二级动力学模型,属于化学吸附过程。与传统有盐染色结果相比,染色后的阳离子化棉纤维色深增加,染料利用率提高。     

Salt-free reactive dyeing of betaine-modified cationic cotton fabrics with enhanced dye fixation

Novel cationic cotton fabrics were prepared by an efficient and simple one-step pad–dry–bake pretreatment process with betaine as cationic reagent. Ester bonds formed between cotton fibers and betaine hydrochloride were proved by Fourier transformed infrared attenuated total reflection(FTIR-ATR) spectra. Moreover, the properties of the cationic fabrics, including X-ray Diffraction(XRD), tensile strength and whiteness and yellowness index,were investigated in comparison with that of the untreated ones. The cationic fabrics were applied in salt-free dyeing of C.I. Reactive Red 195, C.I. Reactive Yellow 145 and C.I. Reactive Blue 19. Different dye fixation processes were applied and compared for untreated and cationic cotton. Dye fixation and color fastness properties of the dyes were tested, and the results presented that dye fixation on the cationic fabrics in the absence of salt was improved with satisfactory light fastness property and applicable wash and rub fastnesses.     

Preparation of betaine‐modified cationic cellulose and its application in the treatment of reactive dye wastewater

Betaine‐modified cationic cellulose was prepared through the reaction of cellulose with betaine hydrochloride by an efficient one‐step dry method. Dicyandiamide was used as a dehydrating agent to promote the formation of ester bonds between the reactants. Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy were used to characterize the cellulose betainate. Experiments showed that at a molar ratio of the cellulose glucose unit, betaine hydrochloride to dicyandiamide, of 1:1:0.5 at 150°C for 3 h, the degree of substitution of the cationic group reached 0.80. The adsorption of simulated C. I. Reactive Red 24 and C. I. Reactive Red 195 wastewater on the cationic cellulose was carried out, and the effects of the adsorbent dose, initial dye concentration, and salt concentration on the dye removal efficiency were investigated. The equilibrium adsorption isotherm data of the cationic cellulose exhibited a better fit to the Langmuir isotherm model than the Freundlich one. The experimental results suggest that the prepared cationic cellulose materials show potential application for reactive dye wastewater treatment. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40522.     

Removal of reactive dyes from wastewater by acrylate polymer beads bearing amino groups: isotherm and kinetic studies

The aim of this study was to prepare a novel resin for the removal of reactive dyes from aqueous media. To prepare the resin, poly(2‐hydroxyethyl methacrylate/ethylene glycol dimethacrylate) beads were grafted with poly(glycidyl methacrylate) by surface‐initiated atom transfer radical polymerisation. Epoxy groups of the grafted polymer were modified with tris(2‐aminoethyl)amine ligand. The modified resin was characterised by swelling studies, FT‐IR and SEM. Three different reactive dyes were selected (CI Reactive Brown 10, CI Reactive Red 120 and CI Reactive Green 5) and used in the removal studies. The effects of pH, temperature, ionic strength and initial dye concentration on the adsorption capacity of the resin were investigated. The adsorption capacity of the resin for Reactive Brown 10, Reactive Red 120 and Reactive Green 5 was 0.029 ± 0.010, 0.032 ± 0.0019 and 0.042 ± 0.0013 mmol/g resin (34.1 ± 1.2, 47.6 ± 2.3 and 69.3 ± 1.7 mg/g resin) respectively. The equilibrium adsorption data were analysed by Langmuir, Dubinin–Radushkevich, Freundlich and Temkin isotherm models. A good fit was found between the Langmuir isotherm and data for the three dyes on resin. The adsorption kinetic data were modelled using pseudo‐first‐order, pseudo‐second‐order and intraparticle diffusion kinetic equations. It was found that the pseudo‐second‐order equation could describe the adsorption kinetics. The results indicated that the modified resin is an attractive alternative for removing reactive dyes from wastewater.     

Influence of liquor ratio and amount of dyestuff in producing ultradeep black dyeing using mercerised and cationised cotton

Cationised cotton allows the dyeing of cotton fabrics without salt and up to 100% anionic dye utilisation. The employment of cationised cotton in the dyeing of high depths of shades with reactive dyes holds marked potential for sustainable improvements through less dye consumption, decreased water usage, and zero salt utilisation, all while obtaining shade depths darker than possible with conventional reactive dyeings. This work builds upon previous work in obtaining ultradeep dyeings of cotton utilising cationised and mercerised cotton by investigating the effects of liquor ratio in dyeing and amount of dye applied. Surprisingly, for mercerised only cotton fabric, it was found that nearly equivalent depths of shade, as indicated by L*, were obtained, irrespective of the liquor ratio and the amount of CI Reactive Black 5 applied from 7% to 10% owf. However, the strengths of the dyeings, indicated by the K/S sum, show slight increases with increasing amounts of dye, but not when the liquor ratio is lowered. Similarly, for mercerised‐cationised cotton, the liquor ratio had a negligible effect on the depth of shade obtained, but increasing the amount of CI Reactive Black 5 resulted in an increase in shade depth and colour strength. Very deep shades with high colour strength were obtained with mercerised‐cationised cotton that were not obtainable with uncationised cotton, even at a very low liquor ratio and with a drastic increase in the amount of CI Reactive Black 5.     

Effects of pressure and temperature on dyeing acrylic fibres with basic dyes in supercritical carbon dioxide

The dyeing of acrylic fibre with CI Basic Blue 47 has been investigated using an ammonium carboxylate perfluoropolyether as an auxiliary in order to perform the reverse micellar system in supercritical carbon dioxide media. The basic dye was satisfactorily solubilised in the interior of the reverse micelle in the system, and dyeability in the supercritical carbon dioxide media was excellent, even in the absence of a retardant and/or an acid. The optimum proton-rich condition for dyeing of acrylic fabric is performed in reverse micelle aggregates and the proton-rich water pool is suitable for dye uptake by the fibre even without the presence of additives. Changes in glass transition temperature of acrylic fibre in the carbon dioxide media also influence the dyeing behaviour of acrylic fabric.     

活性黑KN-B的日晒牢度与染色工艺关系的研究

本文对活性黑KN-B(C.I.Reactive　Black 5)染纯棉织物的染料浓度,固色率和染色后处理条件与日晒牢度的关系,以及三原色拼色时对日晒牢度的影响做了探讨,同时对涤/棉织物两浴法染色的活性黑KN-B与分散蓝HBGL对其日晒牢度的影响做了研究。结果表明:活性黑KN-B染纯棉织物,其日晒牢度随染料浓度和固色率的增加而提高,且固色率为70％以上时,日晒牢度大幅度提高。染色后处理,碱剂与皂煮对日晒牢度亦有一定的影响。使用活性黑KN-B,活性红M-3BE,活性黄M-3RE拼色对织物染色时,在KN-B的浓度为1％以下,其日晒牢度随浓度的增加而下降,在KN-B的浓度超过1％时其日晒牢度随浓度的增加而升高;日晒牢度随活性红M-3BE与活性黄M-3RE的浓度的增加而增大。采用分散/活性二浴法染涤/棉织物,其日晒牢度随KN-B浓度的增加,先降低后升高,在染料浓度大于1％时,日晒牢度几乎不在变化;但其日晒牢度随分散蓝HBGL的浓度的增加而增大。     

Single‐phase ink‐jet printing onto cotton fabric

The current commercial application of ink‐jet reactive inks to cotton fabrics requires pretreating with pad liquor containing a thickener, urea and alkali prior to printing. In this study, attempts have been made to develop a reactive ink‐jet print in a single‐phase process by adding an organic salt to the ink formulation and hence removing the need to pretreat fabrics. This approach utilises inks containing both a reactive dye, in this case Procion Red H‐E3B, and an organic salt such as sodium formate, sodium acetate, sodium propionate or tri‐sodium citrate. The behaviour of a novel reactive ink formulation for ink‐jet printing on to cotton fabric was evaluated at different pH vlaues. The results at optimum pH indicated that printed non‐pretreated fabrics with ink containing organic salts exhibited a higher level of reactive dye fixation than printed pretreated fabric containing no organic salt ink. The yielded prints demonstrate excellent colour fastness to washing and dry/wet crocking properties. The light fastness of the printed fabrics was improved by adding an organic salt to the ink formulation.     

非反应型阳离子助剂在一浴法无盐轧蒸染色工艺中的应用

使用自制的非反应型阳离子助剂对棉织物进行预处理,分别选用活性黄K-RN、活性艳红K-2BP、活性艳蓝KN-R进行一浴法无盐轧蒸染色试验.确定了阳离子助剂处理棉织物的最佳方式和使用的最佳浓度,并与常规有盐染色进行性能对比.结果表明,采用一浴法无盐轧蒸染色对染样的固色率、色光和牢度未产生影响.阳离子助剂的使用能够替代电解质的加入,染料利用率提高25％～40％.棉纤维阳离子化能够在相对较低的温度下进行,提高了该工艺的适用范围,最终达到节能减排的目的.     

安诺素ECO活性染料在纯棉绒类织物上的染色工艺探讨

本文主要对安诺素ECO活性染料在纯棉绒类织物上的染色工艺进行了探讨。并与普通M型活性染料进行了染色效果的对比。结果表明:安诺素ECO活性染料对改善纯棉绒类织物在染色过程中出现的绒底异色、白芯等染色疵病有较好的效果,染色牢度能达到客户的要求。