Search results

Based on clarifying the structural difference between jade fibre and general polyester fibre, this paper aims to study the dyeing properties and dyeing adsorption mechanism of jade fibre with disperse dye and cationic dye.

The chemical structure and microstructure of jade fibre were briefly explained comparing with ordinary polyester fibre. The dyeing rate curve and dyeing adsorption isotherm of disperse dyes and cationic dyes on jade fibre were, respectively, studied. The dyeing uptake, dyeing absorption mechanism, and the main dyeing process parameters were proposed.

Jade fibre can be dyed with cationic dye and disperse dye. The suitable exhaust dyeing process is 110°C and 40 minutes for disperse dye, 100°C and 60 minutes for cationic dye. The dyeing uptake on jade fibre with both disperse dyes or cationic dyes is much higher than that on general polyester fibre and acrylic fibre, and the dyeing adsorption mechanism belongs to the combination of Langmuir and Nernst adsorption for disperse dyes and Langmuir adsorption for cationic dyes. Comparing with ordinary polyester fibre, jade fibre has the advantage of low temperature dyeing and reduced effluent, as is significant to energy-saving and emission reduction.

Jade fibre is a new type of modified polyester fibre with the function of health protection and energy conservation. There are little technical data in the literature at present about the dyeing property of jade fibre.

The paper aims to the preparation of novel disperse dye based on azo salicylaldehyde derivatives TF-A [2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde] and full evaluation of their use as disperse dye TF-ASC [bis 2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde Schiff base with 4,4'-methylenedianiline] for dyeing polyester fabric at various conditions.

The dispersed dye was synthesized via Schiff base condensation in the presence of ceric ammonium nitrate cerium ammonium nitrate 10 mmole% as an eco-friendly catalyst at room temperature. The chemical structure of the prepared dye was characterized via elemental analysis, Fourier-transform infrared spectroscopy, 1H- and 13 C-NMR spectroscopic analysis tools. This study thoroughly examined the dyeing of disperse dye TF-ASC on polyester at various conditions. The characteristics of dyed polyester fabric were measured by colour measurements, as well as light, washing, crock fastness and finally, colour strength. The discrete fourier transform (DFT) theoretical studies, including E_HOMO, E_LUMO and optimized geometrical structure, were assumed and discussed in detail.

The results showed that the synthesized organic dye TF-ASC was highly functional and appropriate for this kind of dyeing method. The dyeing fabrics obtained from disperse dye TF-ASC, properties possess high colour strength as well as good overall fastness properties. These dyes had a high affinity for polyester fabric, with just a tiny change in dye affinity when the pH was changed, even under alkaline circumstances. The dye levelness and shade depth of the colour results were good, and there were a variety of hues from light brownish yellow to deep brownish yellow. The results obtained from DFT computational studies such as E_HOMO, E_LUMO, optimized structure, diploe moment µ and electrophilicity index deduced that prepared organic dye TF-ASC is more applicable as a dispersed dye.

This research is significant because it provides a new dye for dyeing polyethylene terephthalate fibres with exceptional brightness and levelness; the method of preparation is a useful pathway due to its being known as a green chemistry method.

A natural dye is extracted from turmeric and used to dye cotton at different dyeing conditions. Then the fastness properties of the dyeings with different dyeing techniques are compared. The dye is found to have good saturation and rubbing fastness, but poor washing and light fastness properties on cotton, when applied without any mordant. When dyeing is implemented with mordants, washing and light fastness properties show improvement while rubbing fastness exhibits deterioration.

Finally, comparative studies between natural and synthetic reactive dyes reveal that the natural dye has the potential to act as a co-partner with reactive dyes with a few compromises.

Agricultural waste and food sources are some of the pollutants of the environment. One of these wastes is the peel of fruits that cannot be consumed as food. In this regard, walnut husk (WH) and oleaster peel (PO) are known as two important sources of tannin and are bulky wastes. Because of the high percentage of tannin, these materials can be used as a natural source for the preparation of bio-mordant in the dyeing process.

In this study, Reseda and Madder were used as natural dyes in the presence of a mixture of two bio-mordants. WH and PO were selected as bio-mordant. All natural resources are extracted to obtain the juice. The phenolic percentage of tannin-containing extracts was evaluated and then it was used for wool yarns by premordanting method. The results of evaluating the fastness properties using the ISO method.

The most important achievement of this research is the use of agricultural waste in the dyeing process to reduce environmental pollution and create added value. All compounds rich in tannin have some phenolic components, therefore the amount of phenolic content of these extracts was evaluated. The effect of mixing the mordant on the color characteristics of the yarns was investigated and the results showed that changing the ratio of the combination of two mordant is effective on the K/S values. The results of evaluating the fastness properties using the ISO method showed that the washing, rubbing and light fastness in the presence of mordant is good, good and moderate, respectively.

In this paper, to the best of the authors’ knowledge, for the first time, the combination of two natural extracts obtained from agricultural waste has been used to create a new bio-mordant on fibers and improve stability.

Considered as one of the most unwanted species by the International Union for Conservation of Nature, the Prosopis juliflora plant is a noxious and invasive weed. Recent studies suggest that the heartwood of the plant has an unusually high amounts of flavonoids with potential medicinal properties and dyeing potentials. In this work, acetonic extracts were successfully valorized into a natural dye.

After extraction and optimization of dyeing conditions, the fabric was treated by using pre-mordanting, simultaneously mordanting and post mordanting techniques. The dyed samples were then evaluated by using standard methods ISO 105-C06, ISO 105-A02, ISO 105-X12 for wash, light and rub fastness, respectively.

Dye fastness ranged from good to very good with mordants improving both wash and rub fastness. Optimum pH for dyeing was found to be at 7.2 at temperatures of 60°C and a dyeing time of 80 min. Application of mordant in dyeing white fabric showed improved dyeing properties in post mordanting than both pre-mordanting and simultaneous mordanting.

To best of the authors’ knowledge, this paper details for the first time how a noxious weed can be transformed into a natural dye, with potential applications to the textile industry.

This paper aims to develop a novel protocol for the synthesis of disperse dyes derived by a triple cascade reaction with lawsone in presence of Zn acetate as a catalyst. The developed novel scaffolds have efficient dyeing properties on nylon and polyester fibers.

This report demonstrates an effectual triple cascade protocol for the synthesis of novel disperse dyes derived from various polynuclear carbaldehyde, urea and lawsone. The Zn acetate was found to be an effective catalyst for this reaction. Their dyeing performance has been studied on nylon and polyester fabrics. The wash fastness, sublimation fastness, color assessment, determination of percentage exhaustion and fixation properties were applied to both the dyed fabrics.

The obtained results indicate that the Zn acetate is an efficient catalyst for the developed triple cascade protocol. The prepared novel disperse dye greatly impacted their dyeing properties on nylon and polyester fibers. They have shown brilliant shades, higher affinity, adsorption capacity, superior tinctorial strength than the lawsone. The percentage exhaustion value, fixation value, color strength (K/s) value, washing and sublimation fastness properties have been found very well in all dyed nylon samples compared to polyester samples. These results discloses that these disperses dyes are very useful to the growing importance of nylon and polyester fibers.

The present protocol synthesizes the racemic mixture of the prepared molecules.

Developed protocol can be used for various other triple cascade processes. Also these molecules can be used for dyeing of other fabrics.

With the help of commercialization of prepared molecules, it may provide the better alternative of the current disperse dyes. This may affect the various segments of society.

This report represents a novel protocol for the synthesis of modified novel disperse dyes with an efficient dyeing properties on nylon and polyester fibers.

This study aims to show the dyeing behaviour of polyester fabrics using four novel heterocyclic disperse dyes.

The four dyes were synthesized based on 5, 5'-(1, 4-phenylene) bis (1, 3, 4-thiadiazol-2-amine) as a diazonium compound. The UV/Vis absorption spectroscopic data of these disperse dyes while dyeing polyester fabrics were investigated. Following this, the dyeing properties of these dyes on polyester fabrics were investigated under acid condition.

The results showed that increasing the dyeing temperature from 80°C to 100°C led to an increase in dye uptake for all dyes, but further increases of the temperature to 130°C led to higher dye uptake for dye 3 as the dye exhaustion increased by about 50% from 55.9% to 91.4%.

This study is important as it introduces new dyes for the dyeing of polyethylene terephthalate (PET) fibres with colours that range from yellowish orange to bluish yellow and scarlet red and all with excellent brightness, levelness and depth of shade.

This paper aims to find a suitable solution to degrade the C.I. Reactive Red 24 (RR24) dyeing wastewater by using sodium persulphate to recycle water and inorganic salts.

The effects of temperature, the concentration of inorganic salts and Na₂CO₃ and the initial pH value on the degradation of RR24 were studied. Furthermore, the relationship between free radicals and RR24 degradation effect was investigated. Microscopic routes and mechanisms of dye degradation were further confirmed by testing the degradation karyoplasmic ratio of the product. The feasibility of the one-bath cyclic dyeing in the recycled dyeing wastewater was confirmed through the properties of dye utilization and color parameters.

The appropriate conditions were 0.3 g/L of sodium persulphate and treatment at 95°C for 30 min, which resulted in a decolorization rate of 98.4% for the dyeing wastewater. Acidic conditions are conducive to rapid degradation of dyes, while ·OH or SO₄⁻· have a destructive effect on dyes under alkaline conditions. In the early stage of degradation, ·OH played a major role in the degradation of dyes. For sustainable cyclic dyeing of RR24, inorganic salts were reused in this dyeing process and dye uptake increased with the times of cycles. After the fixation, some Na₂CO₃ may be converted to other salts, thereby increasing the dye uptake in subsequent cyclic staining. However, it has little impact on the dye exhaustion rate and color parameters of dyed fabrics.

The recommended technology not only reduces the quantity of dyeing wastewater but also enables the recycling of inorganic salts and water, which meets the requirements of sustainable development and clean production.

The purpose of this paper is to improve the dye affinity of natural dye of Terminalia chebula retzius (T. chebula) using the dye substrate of leather.

The dyeing conditions such as temperature, concentration of dye, and time are controlled by measuring the dye affinity. The effect of enzymatic post-tanning process on dye affinity is evaluated by using different type of proteases such as flavourzyme, alcalase, and bromelain. The optimum conditions for enzymatic post-tanning process are evaluated depending on different pH, temperature, and concentration of enzyme.

The highest dye affinity was obtained at 50°C using a dye concentration of 200 percent (owf) for 30 min treatment by measuring of K/S values of dyed leather. Distilled water was proved as a better extraction liquid to improve the dye affinity of T. chebula. The K/S values of dyed leather were enhanced after the enzymatic post-tanning process by flavourzyme. Moreover, the fastness properties against the rubbing and dry cleaning of the dyed leather were improved by the enzymatic post-tanning process.

In this paper, the enzymatic post-tanning process is introduced as the method to improve the dye affinity in natural dyeing using Terminalia chebula retzius (T. chebula) applied to leather. The results of the study could be applied for further natural dyeing of leather using various natural dyes.

This paper's aim is to evaluate the dyeing performance of newly designed azo dye system based on thiazole substituted for improved dyeing when applied to synthetic fibres.

For improved dyeing qualities, various azo dye systems were synthesised based on polyfunctionally substituted thiazole as the coupling component. The heterocyclic moiety was coupled with diazotised aromatic amines to afford the respective azo or hydrazono systems. The structure of the novel systems was elucidated based on elemental analysis and spectral data. Dyeing performance, electronic spectra and optical properties were characterised based on UV and K/S measurements. Fastness properties were evaluated.

The novel systems were designed so that the functionalities located on the heterocyclic ring afforded structure modification that led not only to good dispersion but also to improved adherence on the fibre. The location of the sites led to constructing a resonating system with higher electron mobility and higher absorption maxima.

The azo dyes, used in the present context were synthesised via a step‐wise pathway leading to new dyes. In addition, the variations in substituents and location of sites on the heterocyclic core could also be studied.

The novel azo dye systems based on polyfunctionally substituted thiazole provided a simple practical access to a series of azo dyes with improved dyeing properties. The availability of starting materials, the simplicity and efficiency to production in good yields and high purity lead to valuable achievements for commercial production.

The designed azo dye systems could find numerous applications as disperse dyes in the fields of dyeing, printing and surface coating. Moreover, the systems can find applications as reactive dyes for wool, silk and cellulosic fibres.