Dye-fiber Bond Research Articles

Sustainable Natural Printing of Cotton Fabric Without Metal-Based Mordant

ABSTRACT Endeavors on scoured and bleached cotton knit fabric to print with natural dyes and natural thickeners were made avoiding the use of detrimental metal-based mordanting agents. Three different natural dye sources (Rose flower-Rosa indica, Teak leaf-Tectona grandis and Tamarind-Tamarindus indica seed husk) extracted in aqueous medium were applied on 100% cotton knit fabric with three different thickeners prepared from the powder of Guar gum-Cyamopsis tetragonoloba, mango seed-Mangifera indica and tamarind seed-Tamarindus indicaon. The printed samples exhibited excellent wash fastness with grading 4–5 for all printed samples, light fastness 7 for tamarind seed husk and tamarind seed, rose flower and tamarind seed printed fabrics and rubbing fastness 4–5 for all printed fabrics. Dye-fiber bond formation was confirmed by FTIR, which revealed phenomena of strong covalent bond between dye and fiber molecules. Environmental impact assessments, chemical oxygen demand (COD) of 0–158 mg/L and total suspended solid (TSS) of 1–55 mg/L indicated that the wastewater generated was safe to discharge to the environment without treatment. Other essential features, determination of K/S value, CIE lab data and durability of printing paste demonstrated successful application of natural dyes and thickeners for printing cotton fabric.

The effect of domestic laundry detergents on the light fastness of certain reactive dyes on 100% cotton

This study presents findings on the effect of several domestic laundry detergents on the fastness to light of selected fiber reactive dyes applied to cotton. Cotton fabric dyed with commonly used reactive dyes were laundered with water only, several domestic detergents, and a laboratory-formulated neutral detergent, and then exposed to light for 2 h in the wet state. Exposures were repeated 15 times, equivalent to 30 h of exposure. Color loss and color difference were measured after 5, 10, and 15 wash cycles, and 10 h, 20 h, and 30 h of exposure. When the fabric was exposed to light wet, the color faded more rapidly than when it was exposed dry. The presence of an oxidizing bleach (sodium perborate or sodium percarbonate) in the detergent increased color loss during washing and wet exposure to light. Ultraviolet radiation from the light source, heat, moisture, alkali, and oxidizing bleach during exposure resulted in hydrolysis of the dye–fiber bond, causing dye desorption during washing and rinsing. The combination of ultraviolet radiation and oxidizing bleaches altered the chemistry of the dye and hence its shade. This was particularly evident on the black dye and one of the navy blue dyes.

A study of reusing vinyl sulfone based reactive dye for dyeing cotton fiber

Reactive dye is a popular dye for dyeing cotton fiber due to its very good color fastness which is explained by the formation of covalent bond between dye and fiber. In this study, practicality of reuse of reactive dye by compensating for the hydrolyzed part of the dye solution is examined. A monofunctional dye (vinyl sulfone type) was used and it was found that dyeing cotton fiber with reused dyebath is possible. Since bifunctional dye can improve the chance of dye-fiber bond formation, vinyl sulfone based bifunctional reactive dyes were also selected in this study. Three types of bifunctional dyes were used and they basically share the same vinyl sulfone group; other reactive groups are monochlorotriazine, dichlorotriazine and vinyl sulfone. Such dyes were chosen in order to compare their respective efficiencies under the effect of one common reactive group. The aim of this study was to compare the effect of hydrolyzed and unhydrolyzed proportions of mono-and bifunctional reactive dyes on cotton fiber and study the possibility and efficiency of the two different reuse dyebath systems.

ChemInform Abstract: Synthesis and Application of Reactive Dyes with Heterocyclic Reactive Systems

Abstract Synthetic methods are described for the preparation of the reactive dyes of the general formula 4 . The dyestuffs have been used f or dyeing cotton according to a uniform dyeing process. Parameters such as the most favourable dyeing temperatures, exhaust and fixing values have been determined. Investigations have been carried out for estimation of the stabilities of bonding between dyestuff and fibre under both acidic and alkaline conditions. Among the triazine dyes, the highest average relative fixation values (70%) are exhibited by the 2-aryl and 2-heteroaryl derivatives. Among the reactive dyes based on pyrimidine, the 5-cyano-2,4-dichloro derivatives show a higher level with 73% while the 2,4-diβuoropyrimidines show the highest level with 84%. The 2,4-diβuoropyrimidine dyes also show the best overall picture with respect to hydrolysis fastness properties, permitting the conclusion that the dye-fibre bonds are stable under both acid and alkaline conditions. The other pyrimidine dyes can be generally regarded as moderate, while the reactive dyes based on triazine showed poor results.

Dye-fiber bond stabilities of the reactive dyed silk

Dye-fiber bond stabilities of the reactive dyed silk

Design and application of a multifunctional reactive dye capable of high fixation efficiency on cellulose

A polyfunctional reactive dye containing two dichloro‐s‐triazine residues linked through aliphatic amino groups via a third triazine system to the chromophoric residue has been prepared. The dye was synthesised stepwise from a specially synthesised 2,4‐dichloro‐s‐triazine dyes. The first step is the reaction of both carbon–chlorine sites in the ‘parent’ dye with 2 mol ethylenediamine under selected conditions of pH and temperature; these conditions ensure that only one of the amino groups in the ethylenediamine will react to give the bis‐2,4‐aminoethyleneaminotriazine dye. The second step is the condensation of 2 mol cyanuric chloride with the two pendant primary amino groups. The alkylamino‐linked dichloro‐s‐triazine dyes show very different dyeing properties when compared with those shown by the parent dichloro‐s‐triazine dye, which has the reactive group linked directly into the aromatic chromophore; in particular, the new dyes have high fixation efficiencies when dyed on cotton at 50 °C and the dye–fibre bond stability to boiling acidic conditions is very good.

Color variations of anthraquinone and azo reactive dyes on cellulose caused by nitrogen oxides under wet conditions

The effects of nitric acid and nitrous acid on the color variations of aminoanthraquinone and azo dyes on cellulose film were examined. The immersion of dyed films in an acidic aqueous nitrite solution led to color variations caused by the diazotization of the amino groups in the anthraquinone and azo reactive dyes examined in addition to the dye–fiber bond scission by acid hydrolysis. When the dyed films immersed in an acidic nitrite solution were exposed to light, the photodecomposition of the diazotized dyes occurred to generate the corresponding phenols via dediazotization, together with the products generated by the photofading of the original dye. No nitrosation of the imino groups was observed for many reactive dyes with imino groups. The color fastness of reactive dyes to nitrogen oxide is primarily attributed to the irreversible color change caused by the apparently direct transformation of amino groups into hydroxyl ones through these processes. Dyes that show larger color changes at higher rates possess lower color fastness to nitrogen oxide.

Synthesis of a new, yellow crosslinking polyvinylamine dye and its crosslinking/dyeing process through a crosslinker

A new, yellow crosslinking polyvinylamine dye was synthesized by the reaction of 2,4-dinitrochlorobenzene with polyvinylamine prepared from Hofmann degradation of polyacrylamide. It was crosslinked and dyed to cotton and silk by a crosslinker synthesized from 1,3,5-trichloro-s-triazine and sodium 2-(p-aminophenylsulfonyl)ethyl sulfate. The crosslinking/dyeing conditions of the yellow polyvinylamine dye, such as pH, cure temperature, and concentration of the crosslinker were investigated. The fixations of the polymeric dye by the crosslinker on cotton and silk were greater than 99%. The crosslinking covalent dye–fiber bond was proved indirectly by the comparison of IR spectra of the undyed fiber, the dyed fiber, and the crosslinked one, and also by the fact that no dye was stripped off from the crosslinked and dyed sample by extraction with DMF/water (1 : 1). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1568–1573, 2006

Reactive dyes containing a 4- m-carboxypyridinium-1,3,5-triazine-2-oxide reactive group: exhaust dyeing of cotton under alkaline and neutral fixation conditions

Two sulphonated reactive dyes, each carrying a 4- m-carboxypyridinium-1,3,5-triazine-2-oxide (triazinyl betaine) reactive group, were applied to cotton under both alkaline and neutral exhaust dyeing conditions and the dyeings compared to those of related chlorotriazinyl and β-sulphatoethylsulphonyl based products. The novel reactive dyes displayed good colour yields under alkaline fixation conditions, but unexpectedly performed very poorly under neutral dyeing conditions. The latter result runs counter to the dyeing performance of commercially available dyes of closely related structure ( Kayacelon React; Nippon Kayaku). The exceptionally poor neutral dyeing behaviour is believed to be due to low substantivity at elevated temperature, a reactive group of low selectivity in acid medium at high temperature, and in part, to an acid labile dye–fibre bond.

The stability of monochlorotriazinyl reactive dyes on cellulose films in aqueous alkaline solutions containing peroxide bleaching agents

The stability of seven reactive (one difluoromonochloropyrimidinyl and six monochlorotriazinyl) dyes on cellulose immersed in sodium peroxoborate (PB) solution (UK–TO solution) containing tetraacetylethylenediamine (TAED) was examined using cellulosic films at 60 °C. The extent of dye loss that occurred from the dyed cellulosic films which were immersed in the UK–TO solution without detergent correlated closely to the ratings obtained using the BS 1006 UK–TO wash test. The dye loss that occurred from the dyed cellophane films was attributed to three contributions, namely, alkaline hydrolysis of dye–fibre bonds, oxidative fading of the dye chromophore by peroxides and cellulose degradation accelerated by PB and TAED. The alkaline hydrolysis of the dye–fibre bond and the extent of cellulose degradation in the UK–TO solution were the main contributions to the dye loss; dye oxidation was a minor factor in the dye loss mechanism. The physical bonding of the dye molecules reinforced the covalent dye–fibre bond stability towards the UK–TO solution.

Dye–fibre bond stabilities of some reactive dyes on cotton

Cotton fabric dyed with commercial reactive dyes of the monochloro-s-triazine, bis(monochloro-s-triazine), and bis(monofluoro-s-triazine) type was treated in buffer solutions pH 10 and 12 at 60, 85 and 98°C. Hydrolysis has been investigated using spectrophotometrical measurements of hydrolysed dye at λ max. The percent of hydrolysed dye was calculated.

The light stability of azo dyes and azo dyeings II. Perspiration–Light stability of dyeings with reactive and non-Reactive derivatives, respectively, of two selected azochromophores

The perspiration–light stability of RC-dyed (conventional reactive dyeing) and N-dyed (substantive dyed without subsequent rinsing) cotton fabric dyeings produced with the members of ‘A’-dye and ‘B’-dye groups, respectively, have been studied. Three main factors influence the perspiration-light stability of the studied dyeings: the nature of the dye–fibre bond, the light stability of the released hydrolysed dye molecules and the action of the salts in perspiration on the latter. The preferred MCT-covalent bonds in the ‘A’-group dyeings lead to higher proportion of released dye molecules in acidic perspiration under exposure, than the preferred, and to a lesser extent to acid sensitive VS-type bonds in the ‘B’-group dyeings. Covalently fixed dyes in dyeings result in much better perspiration-light stability than dyeings with released hydrolysed dye molecules, and the difference in light stability between hydrolysed dye molecules of the two dye groups, as well as their different salt sensitivity, result in improved perspiration–light stability compared to light stability in the ‘B’-group dyeings, and lower perspiration–light stability compared to the light stability in the ‘A’- group dyeings.

Fixation characteristics of carboxylated dyes on polyamide fibres

Reactions of dyes, some of which contain a carboxylic acid group, on polyamide have been investigated using nine different dyes of differing chemical structures. Fixation characteristics and dye–fibre bond stability to alkaline washing were also studied. Light fastness and ability to cover barre effects on nylon were investigated. Studies were also made on the effect of carbodiimide on fixation and dye–fibre bond stability of these dyes on nylon fibres.

The stability and reversibility of the dye-cellulose bond for vinylsulfonyl reactive dyeings

The alkaline hydrolysis of eleven vinylsulfonyl (VS) reactive dyes (F-type) fixedon cellulose was examined at 50°C and pH 10-9. The reversibility of the dye-fiber bond was verified by the cylindrical-film-roll method, dyed and undyed cellulophane being used. The F-types were decomposed to yield the VS types, which were further hydrolyzed to yield the hydroxyethylsulfonyl types or reacted with cellulose to re-form the F-types. The F-types are composed of two kinds of species, presumed to arise from initial VS reaction with cellulose 6-OH or 2-OH, which showed fast and slow rates of bond scission, a himodal hydrolytic behavior. CI Reactive Orange 7 and CI Reactive Yellow 17, which have a high reactivity with cellulose and a high initial rate of scission, were dyed at a similar ratio for both kinds of F-type and the other VS dyes at a relatively high ratio of the F-type, which undergoes slow hydrolysis.

Studies on the chemical and physical interactions between collagen and leather dyes

Studies on the interactions between collagen and C. I. Acid Yellow 36, an acid dye, have been carried out. Hide powder, both natural and chemically modified, was dyed by an equilibrium dialysis method and the dye–substrate affinities determined. Stripping studies of the dyed samples indicated the nature of the dye–fibre bonds.

Synthesis and application of reactive dyes with heterocyclic reactive systems

Synthetic methods are described for the preparation of the reactive dyes of the general formula 4. The dyestuffs have been used f or dyeing cotton according to a uniform dyeing process. Parameters such as the most favourable dyeing temperatures, exhaust and fixing values have been determined. Investigations have been carried out for estimation of the stabilities of bonding between dyestuff and fibre under both acidic and alkaline conditions. Among the triazine dyes, the highest average relative fixation values (70%) are exhibited by the 2-aryl and 2-heteroaryl derivatives. Among the reactive dyes based on pyrimidine, the 5-cyano-2,4-dichloro derivatives show a higher level with 73% while the 2,4-diβuoropyrimidines show the highest level with 84%. The 2,4-diβuoropyrimidine dyes also show the best overall picture with respect to hydrolysis fastness properties, permitting the conclusion that the dye-fibre bonds are stable under both acid and alkaline conditions. The other pyrimidine dyes can be generally regarded as moderate, while the reactive dyes based on triazine showed poor results.

Study on the hydrolysis kinetics of vinylsulfonyl reactive dye-fiber bond

The alkaline hydrolysis rate constants k of dyed cotton fiber were measured for a series of vinylsulfonyl reactive dyes and the alkaline hydrolysis rate constants k' of corresponding model dye-fiber compounds were determined. The structure of the reactive dye largely determines the rate of hydrolysis of the dyed fiber. There is a good linear correlation between k and K' for the same reactive groups. The hydrolytic behavior of the dyed cotton fiber can thus be explained by reference to the hydrolysis behavior of the corresponding model dye-fiber compounds, thus enabling studies on the mode of hydrolysis of the vinylsulfonyl reactive dye-fiber bond to be made, using MO theory.

RELATION BETWEEN HEATS OF ADSORPTION AND DIPOLE MOMENTS FOR 4-AMINOAZOBENZENES ON CELLULOSE

Heats of adsorption (ΔH°d) of series of 4-Aminoazobenzenes (4AABs) on cellulose from the aqueous solutions were determined, and the relation between ΔH°d and the dipole moments (μ) of 4AABs was discussed; ΔH°d values were regarded as the measure of the dye-fiber bond energy.The results obtained showed that ΔH°d decreases with an increase in μ, i.e. the dye-fiber bond energies increase with μ. This fact indicates the contribution of dipole force of the dye to the adsorption on cellulose.The fact can be interpreted by the difference in region in cellulose, on which the dye or water molecules are adsorbed; the dye molecules are adsorbed on a region, water molecules are absent.

Lightfastness of Lanasol (Acid Reactive) Dyes on Drawn and Undrawn Nylons

Four Lanasol (acid reactive) dyes applied on drawn and undrawn samples of nylon in both the fixed and unfixed state were examined for lightfastness on the Fade- Ometer. Higher lightfastness on drawn nylon can be attributed to the "diffusion- restriction" effect, and this higher lightfastness also shows that these dyes are probably in a state of very low aggregation. The fixed dyeings are not more fast than the unfixed ones, showing that the dye-fiber bond obtained in reactive dyeing does not seem to contribute to higher lightfastness.

Dye-Fiber Bond Stabilities of Reactive Dyes Containing Phosphonic Acid Groups

Dyes containing phosphonic acid groups as reactive links to be bonded to cellulose hydroxyl groups have been recently introduced into commercial use. In this investigation, the stability of the dye-fiber bond in reactive dyeings of this type on cotton fabrics has been determined by measurement of the rate of hydrolysis in the pH-range 2.2-8.6 at 98°C. The results demonstrate that this class of reactive dyes has dye-fiber bond stabilities that are in the same range as those of the other major classes of reactive dyes investigated previously. The dye-fiber bond stabilities reflect the wet-fastness properties of these dyeings.