Dyeing properties of net‐modified cotton fabric with triazine derivative containing the multireactive and multicationic groups

Cotton fabric was modified with a 1,3,5‐triazine derivative containing the multireactive and multicationic groups, 2,4,6‐tri[(2‐hydroxy‐3‐trimethyl‐ammonium)propyl]‐1,3,5‐triazine chloride (Tri‐HTAC). Compared with unmodified cellulose, the net‐modified cotton cellulose has different dyeing properties. The modified cotton was dyed with reactive dyes without the addition of salt. The color yield was higher than that on unmodified cotton, despite the addition of large amounts of salt in the latter case. After dyeing, compared with unmodified cellulose with reactive dyes, the reflectance spectrums of modified cotton did not change. The modified cotton got better wash fastness than the unmodified cotton. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4388–4392, 2006     

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.     

Improving the environmental and economic aspects of cotton dyeing using a cationised cotton†

One approach to improve the affinity of anionic dyes for cotton is to add cationic dye sites to the fibre. The dyeing behaviour of cotton that had been rendered cationic by reaction with 2,3‐epoxypropyltrimethylammonium chloride was examined. Dye yields and fastness properties are reported for a number of direct, reactive and acid dyes with the modified fibre. Excellent dye yields and colour fastness properties were obtained without the use of electrolytes, multiple rinsings or fixation agents which are normally employed in cotton dyeing.     

Diffusion properties of reactive dyes into net modified cotton cellulose with triazine derivative

Cotton fabric is chemically modified with a 1,3,5‐triazine derivative containing multireactive and multicationic groups. The diffusion properties of the reactive dyes into net modified cotton cellulose are investigated. When the dyeing temperature is raised, the dye uptake increases gradually and approaches equilibrium after dyeing for 60 min. The diffusion coefficients at different temperatures and the activation energy of the dye are discussed. Compared with unmodified cellulose, the diffusion kinetics of the dye in the net modified cotton cellulose show significant changes. The activation energies of dyes in net modified cotton fibers are much lower than those of dyes in unmodified cotton. The dyeing behavior of the modified cotton is analyzed and compared with the unmodified cotton. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2166–2171, 2007     

A significant approach to dye cotton in supercritical carbon dioxide with fluorotriazine reactive dyes

A series of fluorotriazine reactive dyes have been synthesized and applied to dye cotton in supercritical carbon dioxide (scCO₂) with good dyeing results. The pieces of cotton to be dyed were previously presoaked in a protic solvent and cosolvents were applied during dyeing. The colour strength of the dyeings was evaluated by K/S measurements. The K/S values achieved on cotton dyed were up to 35.8 ± 4.2. Even after the cotton was subjected to a Shoxlet extraction at 358 K for 1 h, a maximum K/S value of 20.2 ± 1.8 was measured. The percentage of dye molecules chemically fixed to the cotton was on average 85%. The excellent reactivity of fluorotriazines allowed a reduction of 3 h on the dyeing time. It is noticeable that a dye concentration of 10% on weight of the fibre (owf) can be applied to dye cotton with fluorotriazines, since no damage of the cotton fibres occurred, as observed for the chlorotriazines at this high dye concentration.Dyes with fluorotriazine as reactive group were found to be the most preferable dyes for dyeing cotton in scCO₂, as they were able to exceed the limitation of the reaction with the cotton.     

多胺型交联染料在丝、棉纤维上的超高固色效应研究

该文合成了H-酸单偶氮红色、吡唑啉酮单偶氮黄色和1,4-二氨基蒽醌系蓝色四乙烯五胺型交联染料,用无盐浸染或轧染的清洁染色工艺,对所合成的多胺型可交联染料应用于丝绸和棉纤维染色,然后用硫酸酯乙烯砜型交联剂,两浸两轧、焙烘的方法使染色纤维固色。研究结果表明,在pH=4时,该类交联染料竭染率最高,用交联剂固色后交联率均大于99%,最终固色率在78%~99%,接近100%固色,染色纤维耐洗色牢度3级以上,耐摩擦色牢度3级以上,与小分子活性染料相当,还具有一定防皱整理效果。     

Influence of different preparation and dyeing processes on the physical strength of the Ingeo† fibre component in an Ingeo fibre/cotton blend. Part 1; Scouring followed by dyeing with disperse and reactive dyes‡

A study has been conducted to examine the effect of different preparation and dyeing processes on the physical strength of the Ingeo fibre component of an Ingeo fibre/cotton blend. An alkaline scouring process (for the cotton), followed by a two‐bath, two‐stage dyeing process in which the Ingeo fibre underwent a simulated dyeing with disperse dyes, followed by the cotton being dyed with reactive dyes, caused minimal deterioration to the strength of the Ingeo fibre. However, it is considered that problems might arise if the Ingeo fibre was subjected to prolonged dyeing times, particularly at neutral or alkaline pH, e.g. if an excessive number of shading additions needed to be carried out.     

Effect of reactive dyeing on the UV protection affected by knitted fabric made from different types of cotton fibre

In this study, 100% cotton knitted fabrics made from combed cotton and combed pima cotton were dyed with reactive dye, with different dye concentrations. Colour properties such as CIE L*a*b* values as well as dyeing uniformity of the dyed fabrics were measured. The relationships between colour properties and the ultraviolet protection afforded by cotton knitted fabrics were investigated. Experimental results revealed that dye concentration is the most important factor. In addition, only L* values have a direct mathematical relationship with the ultraviolet protection factor; a* and b* values and dyeing uniformity were not found to have a significant correlation with ultraviolet protection factor values. Meanwhile, knitted fabric made from combed cotton fibre has better ultraviolet protection performance than fabric made from combed pima cotton fibre.     

Effect of sulphonation level upon the fixation and build up properties of reactive dyes

A number of closely related dyes, each possessing a single β -sulphatoethyl sulphonyl reactive group and a variable number of sulphonate residues, were prepared and their dyeing behaviour evaluated. As the level of sulphonation of the dyes increased, both fixation efficiency and build up on cotton were reduced. These observations were attributed to increased electrostatic repulsion, between dye and fibre, as the anionicity, or level of sulphonation, of the dyes was increased. In support of this, the build up of a monosulphonated dye with one reactive group, was as good as that of a market leading bireactive disulphonated dye.     

Synthesis and salt‐free dyeing characteristics of cationic reactive dyes containing polyetheramine segments

A series of cationic reactive dyes containing both quaternary ammonium and polyetheramine as soluble groups and monochlorotriazine as a reactive group have been synthesised and applied to cellulose fibre by salt‐free exhaust dyeing. Investigation of the synthesis method and dyeing properties of these cationic reactive dyes showed that the best pH value for these dyes is 6, and also that these cationic reactive dyes give a high substantivity to cellulose. In the salt‐free dyeing process, their adsorption was consistent with the Langmuir isotherm during the primary exhaustion stage, but in the secondary exhaustion stage the adsorption was in accordance with the Freundlich isotherm, and their secondary exhaustion reached up to 96% and above. Moreover, the degree of fixation, the levelling, and the transfer properties on cotton fabric were good. Light fastness reached grade 5–6, washing, perspiration, and dry rubbing fastness reached grade 4 and above, but wet rubbing fastness reached only grade 3–4.     

Prediction of recipes for cotton cationisation and reactive dyeing to shade match conventionally dyed cotton

Cationisation allows cotton to be dyed with anionic dyestuffs (including anionic pigment dispersions) without the need for salt, and with decreased usage of dye, water, and energy. Appropriate cationisation levels play a part in dyeing properties such as fabric levelness, in fastness properties such as lightfastness, and in the overall cost of the cationisation treatment. The objective of this work is to assess whether it is possible simultaneously to predict a dye recipe and cationisation treatment level for cotton to yield a colourless or nearly colourless dyebath at the completion of the dyeing to match the shade of conventional fibre reactive dyeing of cotton. It has been shown that it is possible to model a cold pad batch cationisation process, relate the colour yield data and cationisation level for individual dyes, and finally predict a dyeing recipe and the required corresponding cationisation treatment to match the shade of conventional fibre reactive dyeing of cotton. The predicted dye recipe and cationisation amount yield colourless or nearly colourless dyebaths at the conclusion of the dyeing process.     

Process of dyeability modification and bleaching of cotton in a single bath

Graft polymerisation of the cationic monomer, methacryloylaminopropyltrimethylammonium chloride (MAPTAC), onto scoured cellulose was carried out in the bleaching process, aiming at modifying the fibre using a single bath. The extent of MAPTAC fixation on cellulose was measured. The bleaching performance of hydrogen peroxide in the presence of the modifying agent was found to be slightly reduced. The modified bleached cotton fabric was then dyed with a commercial reactive dye in the absence of salt. The dye uptake and colour strength of the modified fabric was markedly increased with an increase in the concentration of MAPTAC. This was attributed to the presence of the cationic groups of the MAPTAC which played a crucial role in attracting the anionic dyes from the dyebath. The results suggest that the dyeing properties of the modified fabric are closely dependent on the efficiency of MAPTAC fixation on cellulose during concurrent modifying and bleaching of cotton.     

Dyeing Properties of Reactive Cationic Dyes Containing a Vinyl-sulphonvl Group on Acrylic Fibre Blends

The preparation of reactive azo cationic dyes containing a vinylsulphonyl group derived from 2-aminobenzothiazole and its derivatives is described. Their dyeing properties on blends of acrylic–cellulosic, polyester–cellulosic fibre and on cotton and synthetic fibres are investigated. The relationship between absorption spectra and pH of dye solution is assessed.     

Influence of different preparation and dyeing processes on the physical strength of the Ingeo† fibre component in an Ingeo fibre/cotton blend. Part 2; Bleaching followed by dyeing with disperse and reactive dyes‡

A study has been conducted to examine the effect of a vigorous alkaline scour–bleaching preparation, followed by high temperature dyeing, reduction clearing and a reactive dyeing process on the physical strength of the Ingeo fibre component of an Ingeo fibre/cotton blend. The results indicate that the physical strength will be retained at a technically‐ and commercially‐acceptable level provided that prolonged high temperature processing times are not employed.     

Chemical modification of cotton to improve fibre dyeability

A new fibre-reactive quaternary compound containing an acrylamide residue was synthesised and used as a cotton modification reagent. The agent was applied to cotton fabrics using a pad-bake process. It was found that the treated fibre could be dyed with reactive dyes without the addition of salt or alkali. The reactive dyes were almost completely exhausted and showed a high degree of covalent bonding with the pretreated cellulose. The effect of varying the pretreatment conditions was investigated and the optimum conditions for pretreating and dyeing were established.     

Protection of lyocell against fibrillation. Part 2: Application of 4,6-(p-β-sulphatoethylsulphonyl)anilino-1,3,5-triazin-2(1H)-one to lyocell by an exhaust process

An exhaust application method for 4,6-( p - β -sulphatoethylsulphonyl)anilino-1,3,5-triazin-2(1 H )-one to dried lyocell fibre has been developed. The procedure employs a temperature gradient technique with all of the salt and alkali present at the start. This method gives consistent wet abrasion resistance values with a standard deviation only marginally inferior to Tencel A100. Subsequent dyeing of lyocell fibres, in turn with two reactive dyes, gave build-up profiles indistinguishable from untreated fibre. The lyocell–agent bonding was stable to high temperature polyester dyeing conditions at pH 6, but unexpectedly showed some instability (as evidenced by a fall in wet abrasion resistance values) when subjected to base-catalysed reactive dyeing conditions.     

Behaviour of Bifunctional and Polyfunctional Reactive Dyes Applied to Cotton Cellulose

Analytical techniques, viz. electron microscopy, surface area determination, and swelling in cadoxen solvent, have been used to obtain results which provide positive evidence for the formation of crosslinks between adjacent cellulose chains in cotton dyed with different classes of bi- and poly-functional reactive dyes. Reactive dyes selected include those where either the reactive groups are present in the same nucleus (dichlorotriazinyl, monomethoxymonochlorotriazinyl, dichloroquinoxaline, trichloropyrimidinyl and difluoromonochloropyrimidinyl) or where the two reactive groups are present at different positions in the dye molecule (Procion HE (ICI) and Procion Supra (ICI)). The extent of changes observed in the morphology of cotton fibre as a result of dyeing with bi- and poly-functional reactive dyes has been found to depend on the amount of dye present in the fibre and the conditions of application.     

Non‐aqueous dyeing of cotton fibre with reactive dyes: A review

This study reviews the evolution of and recent developments in non‐aqueous reactive dyeing systems for cotton fibre. As conventional water‐based reactive dyeing causes adverse effects to the environment because of the need for huge quantities of water and chemicals, as well as generating a substantial amount of effluents, one of the alternative ways to alleviate pressure on the environment is to switch the dyeing medium from an aqueous water‐based approach to a non‐aqueous solvent‐assisted approach. Among a wide variety of non‐aqueous dyeing methods, this review focuses on several non‐aqueous dyeing systems, including dyeing textile fibres with chlorinated solvents, dyeing cotton with the use of reverse micellar systems, a dye/solvent suspension system and a non‐nucleophilic solvent‐assisted dyeing system.     

Application of polycarboxylic acid sodium salt in the dyeing of cotton fabric with reactive dyes

In this study, the effects of polycarboxylic acid sodium salt on the dyeing of cotton with reactive dyes were evaluated by measuring and comparing the K/S values and dyeing fastnesses of the dyed cotton fabric samples. Results showed that the K/S value and dyeing fastness of cotton fabrics dyed with polycarboxylic acid sodium salt, substituting inorganic salts as exhausting agent were close to that of with sodium chloride when dip‐dyeing process was used. While, in pad‐dry dyeing, the K/S value of cotton fabric samples dyed with polyacid salts as exhausting agent was higher than that of with sodium sulfate, and the dyeing fastnesses of these samples were nearly the same. The dyeing mechanism of cotton fabric with reactive dye, using polycarboxylic acid sodium salt as exhausting agent was analyzed. The dyeing exhausting mechanism of reactive dye seems different when the inorganic salt and polycarboxylic acid sodium salt were used as exhausting agent in the dyeing of cotton fabric with reactive dye. The polycarboxylic acid sodium salt, as weak electrolyte, increased the dye‐uptake of reactive dye on cotton fabric not only by screening negative charges on cotton surface, but also by the effect of salting‐out or hydrophobic combination. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effect of various bioscouring systems on the accessibility of dyes into cotton

The effect of four different enzymatic bioscouring systems for cotton have been compared in regard to the dyeability of reactive, cationic and acid dyes. The residual pectin content was determined and the results assessed in terms of dyeability against control samples prepared in the absence of enzyme. The capacity of a bifunctional reactive dye to cover the differences between fabrics treated with different bioscouring treatments was very good. Exhaustion of the cationic dye relative to alkaline scouring was increased by 27.5% and that of the acid dye decreased by 48.2%, indicating that pectin hydrolysis produced an increase in the negative charge on the fibre. The dye exhaustion differences between the four enzymatic systems studied were of significance and confirmed the hypothesis that each enzymatic system provides its own end-groups, resulting in differences in the response of the fibre to dyeing. Enzymatic bioscouring reduces the pollution level of the effluent.