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Some heteropolyfunctional reactive dyes (5a-5n) containing poly(monochlorotriazine and sulfatoethylsulfone) reactive systems have been synthesized by coupling of tetrazotized 4,4’-methylene bis(2-carboxy aniline) with various 4-(ethylsulfurate sulfonyl)anilino cyanurated coupling components (4a-4n) such as H-acid, Gamma acid, J-acid, N-methyl J-acid, N-phenyl J-acid, Chicago acid, S-acid, K-acid, Bronner acid, Peri acid, Laurent acid, Koch acid, Naphthionic acid, and Tobias acid. The synthesized dyes were characterized by nitrogen elemental analysis, IR, and 1H-NMR spectra. They were applied on wool, silk, and cotton fibers. Their dyeing properties, fastness properties, and colorimetric data (L*, a*, b*, C*, H*, and K/S) have also been investigated.

Decamethylcyclopentasiloxane (D5) has attracted an increasing attention because it can realize waterless dyeing of chemical fibers. In this paper, two azo disperse dyes with different substituents were synthesized, and compared with C.I. Disperse Red 73 to study the relationship between structure and dyeing properties systematically in D5 media. The results showed that the dyeing uptake of dyes increased from 85.5 % to 98.0 % with the substituent changing from N-ethyl to N-acetoxyethyl group. This was because the solubility of dyes in D5 media showed an evident reduction. Although the dyes containing N-cyanoethyl group had the lowest solubility, the dyeing uptake became 93.4 %, which was slight lower than that of dyes with N-acetoxyethyl group. This was because an introduction of N-cyanoethyl group increased dye molecular aggregation in D5 media, making it difficult to diffuse. Additionally, the dyes with N-ethyl or N-acetoxyethyl groups showed better washing fastness and rubbing fastness than that of dye containing N-cyanoethyl group. These results provide a potential theoretical guidance for improving exhaustion of disperse dyes in waterless dyeing system. This study will promote textile industry sustainable development.

The weight reduction behavior of short sea-island polytrimethylene terephthalate/polyethylene terephthalate (PTT/PET) conjugate fibers, the dyeing properties of the resulting PTT flock microfibers with five disperse dyes, and the fastness of the flocked fabric were investigated for a new flocking process application, which mitigates the drawbacks of the existing process. The weight reduction ratio of the PTT/PET conjugate fiber depends on the temperature, time, and concentration of the sodium hydroxide solution used in the alkali treatment. The optimum treatment condition to obtain the theoretical weight reduction ratio and PTT microfiber separation was determined using scanning electron microscopy (SEM). When the PTT flock microfibers were dyed with five disperse dyes, the adsorption or dyeing rates of the low- and medium-energy disperse dyes were higher than those of the high-energy disperse dyes. The high-energy disperse dyes exhibited good color yield, suggesting good build-up properties. The wash fastness was poor to good, the rubbing fastness was poor to moderate, and the light fastness was fair to moderate.

Cotton, wool, polyester, and polyamide fabrics have been dyed with the aqueous extract of curcumin, attempting to replace synthetic colorants with natural ones. All dyeing processes were carried out without mordants in aqueous baths in the presence of dispersing agent. It was found that curcumin has high coloristic power on both natural and synthetic substrates offering dark yellow shades. The wash fastness tolerance on all substrates was excellent classifying curcumin as a universal natural dye being able to effectively dye both natural and synthetic fibers, and thus possibly replacing the synthetic and sometimes toxic and allergenic synthetic dyes. It was also found that its antioxidant and antibacterial behavior is considerable, providing useful characteristics to the substrates applied.

Free radical graft polymerization of diallyldimethylammonium chloride (DADMAC) on cotton was employed to substantially improve the dyeability cotton with reactive dyes under salt-free conditions. The effects of plasma-induced graft polymerization of DADMAC on cotton, followed by dyeing with different reactive dyes, was characterized by Fourier transform infrared spectroscopy. A color fastness wash test was conducted to evaluate the effectiveness of cotton cationization on reactive dye fixing. The results show that the salt-free dyeing process with reactive dyes was effective after cationization modification, and the dye uptake rate and dyeing depth are higher than the conventional dyeing techniques.

In this study, polyester fabric was dyed with madder as an environmentally friendly natural dye. According to Box-Behnken experimental design, 46 samples were dyed under various levels of five parameters including dye concentration, dyebath pH, temperature, time, and liquor ratio, and the color strength (K/S) of the dyed samples was measured. To evaluate the effect of each parameter on the color strength, the data was evaluated using multiple analysis of variance. Then, the artificial neural network (ANN) and fuzzy logic models were used to predict the measured K/S values. As both models contain different parameters, the genetic algorithm was implemented to optimize the model accuracy. It was observed that the best obtained ANN and fuzzy models can predict the K/S values with mean absolute percentage error of 2.52 and 3.01, respectively. Also, the effect of each input parameter on ANN was determined according to the partial derivative method and it was found that the maximum and minimum effects on ANN corresponds to dye concentration and liquor ratio, respectively. Finally, the effects of each dyeing parameter on the color strength was investigated based on the established optimal ANN model.

There has been lately a phenomenal rise in the use of natural dyes in different areas, although the principal problem with these natural dyes is their high cost for the production. The main idea of this study is to convert the waste of saffron flower to an eco-friendly natural colorant for sustainable textile coloration of wool fabric. This work studies the stability of saffron flower extract (SFE) by UV-Vis spectroscopic analysis, thermo-gravimetric analysis, and differential scanning calorimetry, the use of mordants, and the color fastness of wool fabric dyed. SFE has good thermal and pH stability under acidic conditions; it would be suitable for textile dyeing processes. The optimized dyeing conditions such as: dye concentration of 6 % for direct dyeing and 2 % for mordant dyeing (dyeing in the presence of mordant), pH value of 3, dyeing temperature of 90 °C, and dyeing time of 60 min are obtained for better dyeing performance of wool with about 60 % bath exhaustion rate after pre-mordanting. A range of colors from brown to green are obtained with good fastness to washing, wet and dry rubbing, acid and alkaline perspiration, and an acceptable color fastness to light. In general, the abundantly available agricultural by-product SFE has considerable potential to be utilized as a natural textile dyestuff.

The poor compatibility between a Fe2O3 pigment and a blend of ultrahigh molecular weight polyethylene (UHMWPE)/polyolefin (PO) can result in low spinnability and poor mechanical properties of the resulting fiber. This study modifies the surface of a Fe2O3 pigment with a titanate coupling agent for dope dyeing melt-spun UHMWPE fiber. The effects of the coupling agent dose, reaction temperature and reaction time on the surface properties of the pigments are investigated. In addition, the characteristics of the UHMWPE blend and colored fibers (by dope dyeing with modified and unmodified Fe2O3 pigments) are compared. Notably, 3 wt.% coupling agent in regard to the pigments mass, a coupling agent to toluene mass ratio of 1:5, a reaction time of 30 min, and a reaction temperature of 80 °C achieve the optimal results, which are a 48.4 % lipophilic degree of the modified pigment, a zeta potential of 48.4 mV, and a contact angle of 144.3°. Moreover, SEM images and torque results of the blend melt show that the compatibility between the Fe2O3 pigment and UHMWPE/PO blend is significantly enhanced. With an increasing pigment content, the mechanical properties of the colored fibers decrease, and the K/S values of the colored fibers increase.

Polyvinylamine (PVAm) was investigated as a pretreatment auxiliary for salt-free reactive dyeing of calcium alginate fibers in this study. The effects of pretreatment conditions and dyeing conditions on the dye exhaustion (E%) were studied by using six reactive dyes. Relatively high E% of 91–98% and 61–80% were obtained by using three monochlorotriazine/sulfatoethylsulfone reactive dyes and three dichloro-s-triazine reactive dyes, respectively. The dyed fibers were able to maintain high color fastness and tensile strength. Adsorption isotherm of reactive dyeing and XPS analysis were also applied to investigate the mechanism of multi-interactions among reactive dyes, PVAm, and calcium alginate fiber. It was concluded that PVAm was an effective pretreatment auxiliary for salt-free dyeing of alginate fibers with reactive dyes.

The surface of wool comprises overlapping cuticle scales that hinder processing of the fiber. Enzymatic modification is widely used for damaging or removing cuticle scales in wool. However, common protease enzyme has poor hydrolysis ability on wool (85 % are keratin) due to specificity of the enzyme, resulting in low modification effect on wool. A novel and effective method was developed to circumvent this limitation resulting in wool with excellent anti-felting, anti-pilling and dyeing properties using proteinase K, a special protease that can effectively degrade keratin. Analysis showed that proteinase K had high affinity for keratin, making it more inclined to hydrolyze the scale layer than the cortical layer compared with commercial proteases Esperase 8.0L and papain. Area shrinkage (4.7 %) of samples treated with proteinase K was significantly lower compared with the area shrinkage of untreated samples (18.5 %), thus complying with machine-washable requirements. A pilling-free modified fabric was obtained with a small enzyme dosage (8 U/g) and the percentage of dye uptake of the wool fabric increased by 100 % compared with original fabric.

The susceptibility of cellulose acetate fibers to alkaline hydrolysis makes it difficult to ensure high wash fastness, due to restrictions imposed by the application of conventional reduction clearing as an aftertreatment. A series of high-washability azo disperse dyes containing a fluorosulfonyl group was synthesized, and their dyeing and fastness properties on cellulose diacetate fibers were investigated. The dyes exhibited reasonable levels of build-up and excellent color fastness on the cellulose diacetate fibers. Samples subjected to aftertreatments of soaping and hot rinsing, as well as the non-treated dyed samples, exhibited similarly excellent levels of wash fastness owing to their outstanding wash-off properties. Based on the results, 4-amino-4′-fluorosulfonylazobenzene disperse dyes can be promising alternatives to high-value-added dyes, as the former can provide high color fastness on cellulose diacetate without excess wastewater discharge during washing.

The effects of atmospheric air plasma treatment based on dielectric barrier discharge (DBD) technology on the surface alteration of a woven polyester (PET) textile fabric were investigated. Chemical and physical surface modifications were characterized by specific wettability measurements (water contact angle-WCA and % capillarity), scanning electron microscopy (SEM), zeta potential assessments, Fourier transform infrared spectroscopy (FTIR) and chemical quantification analysis using ortho-toluidine blue (TBO) dye before and after the DBD processing. A striking enhancement of capillarity percentage from 1.6 % to 108 % was ensured by the plasma treatment suggesting that special chemical elements such as hydroxyl, carbonyl, and carboxyl groups were embedded on the polyester surface, thereby offering it a new hydrophilic behavior. The morphological analysis revealed that plasma treatment is a suitable mechanism to enhance the roughness of treated samples improving furthermore the water retention of the fabric and making the structure more adapted to further chemicals applications. The zeta potential and chemical quantification analysis were also of great interest since they reveal overall the same trend as do the wettability measurements and confirms that the extent of surface modification is in big dependency to the selected plasma parameters. Dyeability of untreated and plasma treated samples was also investigated in terms of color strength, in addition to wash and rub fastness. Sufficiently, higher dyeing performances were noted for plasma treated polyester when compared to the untreated fabric. Atmospheric air plasma treatment was found to be an effective approach to boost the technical reactivity of PET fabrics opening up new opportunities for surface modification under the growing environmental and energy-saving concerns.