Thiazole based disperse dyes for nylon and polyester fibers

Nine disperse dyes have been synthesized by diazotization of 2-amino-4-(p-nitrophenyl)-5-nitrothiazole and coupled to substituted N-alkylanilines. Spectral properties in the IR and visible range of the dyes obtained were investigated. The dyeing performance of these dyes was assessed on nylon and polyester fibers. These dyes were found to give reddish brown to bluish violet shades on dyeing with very good depth, brightness and levelness on nylon and polyester fibers. The dyed fibers showed fairly good light fastness, very good to excellent fastness to wash, rubbing, perspiration and excellent fastness to sublimation. The dyebath exhaustion and fixation on the fiber were found to be very good.     

A new method for brightening wool in a dye bath

A new method for brightening wool during dyeing has been developed using tert-butylamine borane in the dyebath. The method was found to be significantly superior to current industrial practice using hydroxylammonium sulphate or its derivatives. The effects of tert-butylamine borane on dye shades and dyeing quality have also been assessed with a range of commercial wool dyes. The results of this study have shown that the new method is effective in preventing hydrothermal wool yellowing during dyeing, and can produce brighter shades of dyeings without significantly altering the dye shades or impairing the dyeing fastness and mechanical properties of the dyed wool under the conditions examined. The advantages of the concurrent bleaching and dyeing method over conventional bleaching and dyeing processes include reduced processing time, improved energy efficiency, and lower water consumption, arising from reduction in the number of fiber treatment steps.     

A novel eco-friendly colorant and dyeing method for poly(ethylene terephthalate) substrate

Although madder (Rubia tinctorum) has been used as a well-known natural textile dye source for dyeing of natural fibers such as wool, silk and cotton, 100 % polyester dyeing with madder is not common. In this study, polyester samples were dyed with madder at different dyeing temperatures, from 60 °C to 130 °C, in company with 7 chemical and 5 natural mordants. Color properties and rub, light and wash fastness performances were investigated. Different shades of orange, brown, pink and reddish green colors were obtained. Dyeing at 130 °C exhibited the highest color yield, the highest chroma and the lowest lightness values. Overall, chemical mordants exhibited higher color yields than natural mordants. High wash fatness, moderate light and rub fastness levels were observed. The potassium bitartrate and gallnut, a natural mordant, exhibited the best results. The madder dyeing of polyester should be carried out at hot temperature conditions, 130 °C, in order to obtain the highest achievable color yield and chroma with the highest light and wash fastness properties.     

Dyeing properties of mixture of ultrafine nylon and polyurethane with different types of dye

The dyeing and color fastness properties of levelling type acid dye, milling type acid dye, metal complex dye and reactive dye on ultrafine nylon, polyurethane fiber/film and their mixtures were investigated. Ultrafine nylon was dyed well with four types of dye at pH 3-6, but levelling type acid dye showed low washing fastness. Amine-rich polyurethane fiber exhibited enhanced dyeability due to amino groups which acted as dyeing sites, compared to regular polyurethane fiber. In simultaneous dyeing with milling type acid dye and metal complex dye, amine-rich polyurethane fiber absorbed more dye molecules than ultrafine nylon, the color difference between two fibers were apparent. Polyurethane-impregnated ultrafine nylon was also prepared and its build-up properties were determined. It was found that polyurethane whose soft segment was composed of polytetramethylene glycol (PTMG) and polypropylene glycol (PPG) showed improved dyeing property and subsequently high color strength.     

Dyeing characteristics of Nylon,cotton and N/C mixture fabrics with reactive-disperse dyes containing a sulphatoethylsulphone group

The dyeing and color fastness properties of three reactive-disperse dyes containing a sulphatoethylsulphone group on Nylon, cotton and N/C mixture fabrics were examined. Reduction-clearing was more effective in removing the unfixed dyes than soaping since the reactive-disperse dye became hydrophobic during dyeing process. Nylon was dyed well with three reactive-disperse dyes at pH 5∼8 and difference in chemical structure between dyes did not affect the final color strength of the dyed Nylon fiber, but their build-up properties on Nylon were not so good. The color strength of the dyed cotton was not as high as that of Nylon. The color strength of cotton increased by lowering dyeing temperature when the reactive-disperse dyes having hydroxy group were used. Nylon absorbed more dye molecules than cotton in simultaneous dyeing, the color difference between Nylon and cotton could be reduced as the dyeing temperature decreased. N/C mixture fabric was dyed well at 60 °C with the reactive-disperse dyes having hydroxyl group when applied at pH 7 and 60 °C, and their build-up properties were good. It was also found that washing fastness and rubbing fastness of dyed Nylon, cotton and N/C fabrics with the reactive-disperse dyes were excellent, while light fastness was moderate.     

Polymeric dyes based on thiadiazole derivatives

A series of polymeric dyes were synthesized by free radical addition polymerization of monomeric dyes. The 2-amino-5-mercapto-1,3,4-thiadiazole was diazotized and coupled with various N-arylmaleimides to give monomeric dyes. All the polymeric dyes were characterized by elemental analysis, infrared spectroscopy, visible absorption spectroscopy, viscometry, and thermogravimetric analysis. Color and dyeing properties of the polymeric dyes were discussed by comparing them with those of the corresponding monomeric dyes. The dyeing performance of these dyes was assessed on nylon fiber. These dyes were found to give various color shades with good to very good depth and levelness on the fiber. The dyeing of the monomeric dyes showed moderate fastness to light and good to excellent fastness to washing, perspiration and sublimation and their corresponding polymeric dyes showed excellent fastness properties. The dyebath exhaustion and fixation on nylon fiber has been found to be good.     

Natural dye extraction from waste barks of Turkish red pine (Pinus brutia Ten.) timber and eco-friendly natural dyeing of various textile fibers

In this study, a natural dye extraction was carried out to isolate dyestuff extract powder from the waste barks of Turkish red pine (Pinus brutia Ten.) timber which is not a common natural dyestuff source. The natural dyestuff powder obtained was applied to cotton, flax, wool, silk, tencel, polyamide and acrylic fibers accompanied by simultaneous application of alum and natural oak ash mordants. Color properties were investigated including rub-, light- and wash-fastness performance. Differently dyed fiber samples exhibited slightly different shades of beige, brown and brownish-yellow depending on the mordant used and fiber type. Alum mordanted samples exhibited better color properties. The highest (63.4) and the second highest (45.3) f(k) color yield values were observed for alum mordanted silk and wool samples, respectively. Dyed fabrics showed excellent wash fastness, very low staining performance, and moderate light- and rub-fastness.     

Natural dyeing with black cowpea seed coat. I. Dyeing properties of cotton and silk fabrics

A new trial to determine the dyeing properties of cotton and silk fabrics with a black cowpea seed coat as crop waste was investigated. The natural dye anthocyanins were extracted from a black cowpea seed coat in an aqueous solution and used to dye silk and cotton. The optimal conditions for colorant extraction were an aqueous solution of a dried seed coat of black cowpea in a 1:10 liquor ratio at 70 °C for 4 hours with pH of 4. The best dye-uptake of silk and cotton fabric were obtained when the pH was 3.5 and 3.0 respectively, the temperature was 80 °C for 1 hour and the liquor ratio of black cowpea was 1:20. Different colors as dusky brown, brown, faint yellow, light green, reddish brown, cyan and green could be obtained using a various kind of mordants. The depth and brightness of color tones were affected by different dyeing and mordanting pH conditions. The colors of the fabrics were examined using a computer color matching system in terms of the K/S values and CIELAB color-difference values. The dyeing was evaluated using standard light, wash and heat fastness tests. Good wash and heat fastness were obtained but the poor light fastness indicated the need for improvement to fulfill the requirement for textile applications.     

Effects of bleaching and dyeing on the quality of alpaca tops and yarns

This paper reports the effects of bleaching of alpaca tops and dyeing of bleached alpaca tops/yarns on the quality of tops and yarns. A dark brown alpaca top was bleached with hydrogen peroxide. Two bleaching methods were tried for effectiveness of color removal. A portion of each bleached top was dyed after bleaching. Color parameters were examined for unbleached, bleached and bleached/dyed tops, these tops were then converted into yarns of different twist levels and counts using a worsted spinning system. Some of the bleached yarn from each bleaching method was dyed in a package dye vat to compare the difference of top dyeing versus yarn package dyeing on yarn quality. Fiber diameter, yarn strength, yarn evenness, yarn hairiness and fiber degradation were tested to examine the effects of bleaching and dyeing on these properties at top and yarn stages. A processing route for bleaching and dyeing alpaca fiber was recommended.     

Eco-friendly dyeing using natural mordant extracted from <Emphasis Type="Italic">Emblica officinalis G</Emphasis>. Fruit on cotton and silk fabrics with antibacterial activity

Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.     

Dyeing and fastness properties of a reactive disperse dye on PET, nylon, silk and N/P fabrics

Dyeing and color fastness properties of a reactive disperse dye containing an acetoxyethylsulphone group on PET, Nylon, silk and N/P fabrics were examined. The reactive disperse dye exhibited almost the same dyeing properties on PET fabric as a conventional disperse dye except the level of dye uptake. The most appropriate pH and dyeing temperature for the dyeing of Nylon fabric were 7 and 100°C respectively. The build-up on Nylon fabric was good and various color fastnesses were good to excellent due to the formation of the covalent bond. Application of the reactive disperse dye on silk fabric at pH 9 and 80°C yielded optimum color strength. The rate of dyeing on Nylon fabric was faster than that on PET fabric when both fabrics were dyed simultaneously in a dye bath, accordingly color strength of the dyed Nylon was higher. The reactive disperse dye can be applied for one-step and one-bath dyeing of N/P mixture fabric with good color fastness.     

Extraction of natural dye from <Emphasis Type="Italic">Coreopsis tinctoria</Emphasis> flower petals for leather dyeing − An eco-friendly approach

This study evaluated the extraction of two colors of dye (yellow and brown) from Coreopsis tinctoria flower petals using ultrasound and the dyeing of leather with the extracted dyes as a source of nontoxic and eco-friendly dye. The results showed an increase in the dye extraction values with increasing time at 100 W ultrasonic power at 80 °C for 1 h. Leather dyeing was optimized with the aid of ultrasound and magnetic stirring. The optimum leather dyeing conditions, with respect to the dye uptake, dye penetration and intensity of the color, were determined to be 12 % dye concentration, 100 W power, 1,000 rpm, and pH 7.0 for 60 min at 80 °C. It was shown that sonication improves dye exhaustion from a 90 % to 60 % rating for 1 h of dyeing time. The dyed leather was assessed by reflectance measurements and compared with visual assessment data. The fastness properties of dyed leather samples showed good fastness against washing, light, and dry and wet rubbing. The strength properties were not significantly altered and the bulk properties, such as softness, were found to be improved by the use of Coreopsis tinctoria yellow and brown dyes using an ultrasonic and magnetic stirring dyeing process.     

Dyeing of meta-aramid fibers with disperse dyes in supercritical carbon dioxide

Dyeing characteristics of meta-aramid fibers were investigated in supercritical carbon dioxide by employing three disperse dyes and a carrier. The effects of dyeing temperature, pressure, time, dye concentration, CO₂ flow, and carrier concentration on dyeing properties were investigated. The results showed that meta-aramid fiber could be dyed in supercritical carbon dioxide. Its color depth was improved with increasing dyeing temperature, pressure, time, dye concentration, CO₂ flow, and carrier concentration. Moreover, the color depth could be significantly improved by adding the carrier. The dyeing procedure of supercritical carbon dioxide fluid did not influence the chemical structure and antistatic properties of the meta-aramid fiber. The maximum decomposition temperature and breaking strength of the dyed meta-aramid fiber are slightly increased. The dyed meta-aramid fiber in supercritical carbon dioxide had good fastness, which was rated at 4–5.     

Properties of basic dyes on polyacrylonitrile treated m-aramid fabrics

Treatment of polyacrylonitrile (PAN) onto m-aramid fabric was carried out by pad-dry-cure method using dimethylformamide (DMF) dissolved acrylic fiber solution. The obtained PAN treated m-aramid fabric was dyed using exhaustion method with basic dyes. The effect of PAN treatment on fabric stiffness property was acceptable with acrylic fiber solutions ranging from 1 wt% to 4 wt%. Whilst, more than 4 wt% PAN treated fabrics exhibited undesirable stiffness. The dyeing results showed that PAN treated m-aramid fabrics exhibited a significant increase in color strength when compared to untreated fabric, arising from an increase in anionic dye sites (styrene SO₃ ^? group). Wash fastness was comparable to that of untreated fabric, indicating the strong interaction between dye molecules and the PAN. Rubbing fastness of treated fabrics was not affected by treatments with PAN concentrations lower than 4 wt%. Further increase in PAN concentration led to poorer rubbing fastness property due to the problem of surface dyeing. For light fastness, the PAN treatment failed to improve the light fastness property which is the main disadvantage of basic dyeing of aramid fabric. Finally, in case of PAN treatments with the range of 1 wt% to 4 wt%, the flame retardancy property of PAN treated m-aramid fabrics was found not affected by the percent add-on. However, above 4 wt% PAN treatment, the flame retardancy performance became deteriorated.     

Combined use of cationization and mercerization as pretreatment for the deep dyeing of ramie fibre

In order to produce deep shades of colour, ramie fibre was subjected to pretreatment by cationization, caustic mercerization (slack and tension condition), and liquid ammonia mercerization. The untreated and pretreated samples were dyed with 0.5 to 7 % concentrations (on mass of fiber (o.m.f)) of Liyuansol Red FL-2BL reactive dye. The dyeing properties of dye exhaustion, fixation, colour uniformity, wash fastness, and rubbing fastness were investigated. The results indicated that these pretreatments improved dye exhaustion and fixation on ramie fibre, with no loss of fastness. For the untreated and treated substance, the amount of dye mass absorption increased linearly with increased dye o.m.f. Cationic treatment improved performance, with 89 % and 98 % for exhaustion and fixation, respectively, and the maximum K/S values of all fibers receiving pretreatment. The colour uniformity was acceptable and similar for the untreated and treated ramie fibers, with the exception of cationic-treated fabric dyed at 7 % dye o.m.f that showed a high standard deviation value of colour uniformity. The Freundlich and Langmuir adsorption isotherm models were also used to study the adsorption of dye on ramie fibre; all of the adsorption processes fit the Freundlich model.     

1-Aminoanthraquinone Diazonium Salt on the Coupling Modification Dyeing of Silk Fibroin with Enhanced Color Fastness

Chromophore incorporated into the protein chains through residue modification on silk fibroin will be an important way to get new dyeing technology with improved color fastness. Herein, 1-aminoanthraquinone diazonium salt was prepared and used for the modified dyeing on tyrosine of silk fibroin. The silk after modified dyeing was measured by UV-Vis, FTIR, MS, ¹H-NMR, Data color, and other testing techniques. Interestingly, the resulting silk showed excellent rub and wash fastness. The enhanced color fastness is contributed by an electrophilic substitution reaction between 1- aminoanthraquinone diazonium salt and the ortho position of phenolic hydroxyl in tyrosine molecular. Moreover, the mechanical property of silk was protected effectively by the mild coupling modified dyeing, better than the traditional acid dyeing under high temperature for a long time. This facile strategy provides an alternative approach to silk dyeing and benefits the silk applications.     

Cotton Dyeing and Antibacterial Finishing Using Agricultural Waste by an Eco-friendly Process Optimized by Response Surface Methodology

In this study, Berberis vulgaris L. wood as an agricultural waste was used for dyeing and functional finishing of cotton. To facilitate the attachment of natural dye, citric acid was used to create carboxylic acid functional groups on cotton fibers. The process of crosslinking of cotton fabric with citric acid was optimized in order to obtain the maximum dyeability with the cationic natural dye. The effects of three important factors including citric acid concentration, sodium hypophosphite concentration and curing temperature on the color strength of the dyed samples with woods of barberry tree were analyzed by response surface methodology and the optimum conditions for obtaining the highest color strength was obtained. The crosslinking of citric acid on cotton fibers was confirmed by FTIR spectroscopy. The dyed sample prepared under the optimum conditions of crosslinking showed good wash and light fastness properties besides very good antibacterial activity against gram-negative and gram-positive bacteria.     

Extraction, identification and dyeing studies of Isosalipurposide, a natural chalcone dye from Acacia cyanophylla flowers on wool

A chalcone compound Isosalipurposide 1 was qualitatively isolated from Acacia cyanophylla yellow flowers. The dyeing of wool fabrics with this chalcone compound as a natural dye has been studied. The effect of dye bath pH and dyeing temperature were investigated. The obtained shades were bright with generally a good fastness. A post-mordanting method was used in the dyeing of wool with this chalcone dye. It was found that, generally, mordanting improved light fastness especially in the case of zinc sulphate.     

Optimization of dyeing condition for wool/cotton union fabric with direct dye using box-behnken design

Wool/cotton union fabric was dyed with a direct dye in union shade. The dyeing was performed in a single bath in relation to four factors: leveling agent (Lyogen SMKI, 0–1.5 % oww), electrolyte (sodium sulfate, 0–10 %), dyeing temperature (85–95 °C), and dyeing time (15–60 min). The dyeing was characterized by dye bath exhaustion (%), color strength (K/S value), washing fastness, and light fastness of dyed sample. Response surface analysis showed that the exhaustion of direct dye increased with electrolyte, dyeing temperature, and dyeing time while the K/S value followed a linear shape with leveling agent and dyeing temperature. An optimized recipe was formulated based on response surface strategy and numerical optimization solution.     

Dyeing of synthetic fabrics in water using azoic dyes based on boronic acid derivatives

Development of water-soluble dyes for the dyeing of different textile fabrics is essential for the textile industry due to ecological and economical reasons. In this study, a series of new azoic dyes were prepared by diazotization reaction between the phenyl boronic acid and different aniline derivatives, and their dyeing capacity in aqueous solution was evaluated. The synthesized boronic azo dyes present good water solubility and can dye polyamide (nylon), wool, silk, and cellulose acetate fabrics. The effect of factors such as concentration of dye, dyeing temperature, and pH on the level of color strength (K/S) was studied. The dyeing results showed that higher color strength K/S (about 16) and fastness properties (about 4/5) with boronic acid dyes were achieved at higher temperatures avoiding the use of surface agents, mordants, and other polluting chemical additives.