Carrier‐free dyeing of radiation‐grafted polyester fabrics with disperse dyes

Carrier‐free dyeing of radiation‐grafted polyester fabrics with disperse red dye was studied in the temperature range 283–363 K. 1‐vinyl 2‐pyrrolidone (NVP), acrylic acid (AA) or their mixture was used to graft poly(ethylene terephthalate) (PET) fabric. The effects of pH of the dye solution, graft yield (GY), dyeing time (t), dye concentration (C), and dyeing temperature (T) on the colour difference (CD) of PET fabric were studied. The best dyeing condition was achieved at pH 5.5. CD increases linearly with the increase in GY, with slopes depending on the type of grafted copolymer. CD increased rapidly as the dyeing time increased; this was followed by a relatively slow dyeing rate within a few minutes. The initial dyeing rate (R) was found to increase with an increase in C and T. The dyeing rates for all grafted samples followed 0.35‐order kinetics and are temperature‐independent. Average activation energy 9.26 kJ mol^?1 is calculated for the dyeing process and is independent of the fabric treatment. Pre‐exponential rate constants 1976, 1839, and 1579 (CD/GY) s^?1 were calculated for dyeing PET samples grafted with AA/NVP mixture, NVP and AA, respectively, while 1074 CD s^?1 was evaluated for carrier dyeing of ungrafted fabric. Analysis of the kinetic parameters and the dyeing mechanism revealed that dyeing PET fabric was diffusion‐controlled. Grafting PET fabric improved significantly the dyeing affinity of the DR dye over ungrafted samples dyed in solutions containing a carrier. Copyright © 2005 Society of Chemical Industry     

The roles of polymer relaxation phenomena,aqueous dye solubility and the physical properties of water in the mechanism of adsorption of a disperse dye on poly(ethylene terephthalate) fibres: Part 4 further aspects related to polymer relaxation phenomena

To further investigate the contribution of polymer relaxation times to the mechanism of disperse dye adsorption on poly(ethylene terephthalate) fibres, the temperature-dependent uptake of Teratop Yellow HL-G 150% on both cotton and polyamide 66 fabrics at temperatures between 30 and 130°C was compared with that on poly(ethylene terephthalate) fabric. Although uptake of the commercial grade dye on polyester fabric is governed by the thermally regulated, broad glass transition of the water-saturated poly(ethylene terephthalate) substrate, as this was not observed for either cotton or nylon 66 fabrics, the respective cellulose or polyamide 66 polymer glass transition does not present a major thermal impediment to dye uptake over the wide range of dyeing temperatures used. This is because the onset and end-set temperatures of the glass transition of the water-plasticised poly(ethylene terephthalate) material reside within the range of dyeing temperatures employed, whereas those of the water-plasticised cotton and polyamide materials occur below the lowest dyeing temperature examined (30°C). The thermal dependency of disperse dye solubility also likely makes a meaningful contribution to the temperature-dependent dye uptake observed for each type of fibre.     

The roles of polymer relaxation phenomena,aqueous dye solubility and the physical properties of water in the mechanism of adsorption of a disperse dye on poly(ethylene terephthalate) fibres: part 5 analysis of polymer relaxation phenomena for different polymers

The temperature dependent uptake of a commercial disperse dye on cotton and polyamide 66 fabrics at dyeing temperatures between 30°C and 130°C adhered to the Williams–Landel–Ferry equation, insofar as, very good correspondence was observed between plots of experimentally determined colour strength data points (log1/f_k) and the respective structural relaxation times of the cellulose and nylon 66 polymers (loga_T data points), as a function of the parameter (T − T_g). Adsorption of the dye on both types of fibre therefore concurs with the fundamental precept of the free volume model of dye diffusion. Comparison of the adherence of the uptake of the commercial dye on cotton and polyamide 66 fabrics with that secured on polyester fabric revealed that despite the major chemical and physical differences between the three types of fibre, the same dyeing mechanism likely applies to each fibre type. The marked temperature dependent uptake of the commercial grade disperse dye each of the three types of substrate is the consequence of two, different, but inherently interconnected, thermally activated phenomena, namely the relaxation times of the molecular rearrangements occurring within the respective cellulose, nylon 66 or poly(ethylene terephthalate) macromolecule, in which polymer glass transition assumes the principal role, and the aqueous solubility of the commercial grade disperse dye.     

The role of transition metal cations in dyeing of fabrics made from synthetic fibres

The use of d-metal cations in dyeing polyester fabric with dark blue K increases the dyeability to 350%. Use of VO²⁺, Fe²⁺, and Cu²⁺ cations is most effective. It is hypothesized that d-metal cations increase the number of active sites due to vacant atomic orbitals on the valence level so that the polyester fibre can sorb a larger amount of dye. The use of d-metal cations in dyeing polyester fabric increases the resistance of the color to external physicochemical effects.     

Textile applications of photochromic dyes. Part 4: application of commercial photochromic dyes as disperse dyes to polyester by exhaust dyeing

A series of commercial photochromic dyes was applied to polyester fabric as disperse dyes. The photocoloration properties of the dyed fabrics were investigated by applying techniques previously established in our laboratories using an independent source of ultraviolet irradiation and traditional colour measurement instrumentation. The dyed fabrics showed reversible photochromism, developing pronounced colours from weak background colours on irradiation with ultraviolet light and returning to their original state when the ultraviolet light source was removed. However, the extent of photocoloration and the depth of background colour varied significantly with the particular dye used. The dyeing procedure was optimised by maximising the degree of photocoloration, expressed as the colour difference (ΔE₁) between the colour developed after ultraviolet exposure and background colour, while minimising the background colour, expressed as the colour difference (ΔE₂) between unexposed dyed and undyed fabrics. Optimum dyeing concentrations were determined. The colour development and fading properties, fatigue resistance and storage stability of the dyed fabrics were investigated.     

Study of the Influence of Gemini Cationic Surfactants on the Dyeing and Fastness Properties of Polyester Fabrics Using Naphthalimide Dyes

In this paper, the dyeing and fastness properties of three monoazo naphthalimide dyes including different imide groups (dye 1: ethyl amine, dye 2: ethyl glycinate and dye 3: glycine) on a polyester fabric were investigated in the presence of two gemini cationic surfactants (symbolized as 12‐4‐12 or 14‐4‐14) and a conventional single chain surfactant, dodecyltrimethylammonium bromide (DTAB). The color strength (K/S) of naphthalimide dyes on polyester fabric was measured through the reflectance spectrophotometric method, and the values obtained in the presence of different cationic surfactants increased in the order of dye 3 < dye 2 < dye 1. Although the K/S values indicated that the gemini cationic surfactants had almost no effect on the dyeing behavior of dye 1, but they were effective in dyeing ability of dye 2 and dye 3. The data for dye 2 demonstrated that build up of polyester fabrics in the presence of gemini surfactants are more than the conventional cationic surfactant, and also K/S values of dye 3 on polyester fabrics were in the order: DTAB > 12‐4‐12 > 14‐4‐14. It was found that the washing and rubbing fastness properties improved with increasing the concentration of surfactants. In addition, the sublimation fastness of dye 3 was more than the other dyes owing to the presence of a polar group in its chemical structure, and the light fastness of naphthalimide dyes on polyester fabrics was generally moderate.     

Dyeing of Nylon Fabrics with an Acid Dye in a Rotating-disc Contactor

The kinetics of dyeing a nylon fabric with an acid dye (C. I. Acid Blue 182) were investigated using a rotating-disc contactor, and were analysed in terms of intrapolymer diffusion with trimodal (one Nernst-type and two Langmuir-types) adsorption. The resistance of mass transfer from liquor to film in film dyeing was found to be negligible relative to resistance inside the film. The effective interfilament diffusion coefficient in the fabric was found to be dependent on the rotational speed of the disc. It appears that the process of dyeing nylon fabric with an acid dye might be governed by interfilament diffusion of dye in the fabric rather than mass transfer from liquor to fabric and intrafilament diffusion.     

Effect of chitosan on dyeing of chemical fibres

Treatment with chitosan before dyeing significantly improves the properties of fabrics made of polyester and polyamide fibres: it increases the intensity and fastness of the colors of the fabrics; the capillary and sorption properties of the fabrics are improved due to swelling of the chitosan film on the fibre; the mechanism of dyeing textile materials is significantly altered by not requiring penetration of the dye into the depth of the fabric.     

Decolorisation by Bacillus flexus of exhausted dyebaths containing CI Acid Red 249 and their reuse for wool dyeing

A dyebath containing left-over CI Acid Red 249 after dyeing of wool was completely decolorised using an isolated bacteria Bacillus flexus. Optimisation was carried out by varying the pH, temperature, dye concentration, and microbial loading. Complete decolorisation of a 50 mg l⁻¹ dye solution was achieved in 8 h at pH 7 and 37 °C with 10% v/v loading of the bacteria. The decolorised bath was utilised for dyeing of wool fabric with the same dye at 5% shade. This cycle of dyeing–decolorising–dyeing was repeated 5 times. The evaluation of dyed fabric was done using K/S, colour values, and fastness to light and washing. Comparison of a sample dyed with the conventional exhaust process showed that the dyeing quality is not affected for all five successive reuse cycles. The results are important from the viewpoint of reducing water consumption and chemicals.     

Textile with a hydrogel and iron oxide nanoparticles for wastewater treatment after reactive dyeing

In this work, we describe for the first time the synthesis of a hydrogel with iron oxide nanoparticles, uniformly distributed in its structure on a polyamide fabric by surface initiated photopolymerization. The type of outgoing iron ions Fe(II), Fe(III), and the combination between them influences the properties of the iron oxide particles and the obtained composite materials (PAF2, PAF3, and PAF32). All composite materials have been investigated as catalysts in heterogeneous Fenton process for treating real industrial wastewater after dyeing of cotton fabric with reactive dye Drimarene K-7B. Different conditions on the degradation of this dye have been investigated. The best result for discoloration has been obtained with PAF2 at concentration 9.4 g L⁻¹ and pH = 2.2 in the presence of H₂O₂ (93.3 mmol L⁻¹, where 78% of dye was degraded for 24 h and 90.5%-for 48 h. The high salinity of wastewaters, typical for dyeing with reactive dyes favors discoloration, while surface-active agents hinder the process. The obtained material is reusable and is more effective in less polluted water solutions. It has been found that the composite material can be used repeatedly.     

The colour properties of polyester/cotton knitted fabrics coated with poly(N‐vinyl‐2‐pyrrolidone)

The objective of this research was to investigate the use of crosslinked poly(N‐vinyl‐2‐pyrrolidone) (PVP) to coat polyester/cotton knitted fabric, without adversely affecting its dyeing properties. Before dyeing, the knitted fabrics were tested for bursting strength to assess the influence of the coating on their resistance. The dyeing parameters were evaluated as the exhaustion (%), K/S value, colour difference (ΔE), relative strength (RS %) and colour fastness to washing. Bursting strengths were 9.4 for coated and 9.7 kgf cm^?2 for uncoated knitted fabric samples, confirming an insignificant loss in resistance. In the evaluation of K/S, ΔE and RS%, the values for the samples with the highest concentration of PVP were the most different to those for the standard sample. The colour fastness showed satisfactory results indicating that neutralisation and washing after dyeing were effective. These results could lead to increased quality in the textile industry, adding value to products.     

Dyeing kinetics of methacrylic acid grafted polyester fabric with astrazonrot violet and rhodamine red basic dyes

The low‐temperature dyeing kinetics of radiation‐grafted poly(ethylene terephthalate) fabric were studied. The effects of the graft yield (GY), dye concentration, and dyeing temperature on the color difference (CD) of methacrylic acid grafted polyester fabric were studied for astrazonrot violet (AV) and rhodamine red (RR) basic dyes. CD increased sharply with an increase in GY and tended to level off at higher degrees of grafting. The best dyeing conditions were achieved for both dyes at pH 11.5. CD of the grafted fabric increased rapidly as the dyeing time increased; this was followed by a relatively slow dyeing rate within a few minutes, which depended on the concentration and temperature of the dye bath. The initial dyeing rates and rate constants for the AV dye were higher than those for the RR dye. The dyeing process followed 0.14‐order kinetics and was independent of the dyeing temperature or the type of dye. The dyeing rates and rate constants increased with an increase in the dyeing temperature. An Arrhenius‐type plot of the natural logarithm of the dyeing rate constant versus the inverse of the absolute temperature yielded apparent activation energies of 4.9 and 13.8 kJ/mol and pre‐exponential rate constants of 9.4 and 100.6 (CD/GY)s^?1 for the AV and RR dyes, respectively. The mechanism of the dyeing process for the two dyes was diffusion‐controlled, and their dyeing rates depended on the type of basic dye. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1070–1076, 2004     

Interpretation of Colloidal Dyeing of Polyester Fabrics Treated with N‐Cetylpyridinium Chloride in Terms of Zeta Potential and Surface Free Energy Balance

In this work are presented results about the effect on the surface free energy and zeta potential for the adsorption process of the colloidal dye Disperse Blue 3 (DBlue3) onto polyester fabric (dacron 54, stile 777), when the fabric is pretreated with N‐cetylpyridinium chloride (NCPCl). The zeta potential of the fabric as a function of the pH of the liquid phase shows that both H⁺ and OH^? ions are involved in determining the potential. The negative charge of the fiber is caused by the presence of the carboxyl end‐groups of the polyester, which are generated by the acidic and basic hydrolysis of the fabric in these media. The zeta potential of the DBlue3 as a function of the pH of the liquid phase shows that the negative charge of the dye particles are because of the presence of an OH^? group, ionized in aqueous media, in the molecular structure of the dye. The zeta potential of the fabric treated with a 10^?3 M solution of NCPCl as a function of the pH of the liquid phase is positive over the whole pH range. This behavior can be attributed to the presence of the pyridinium group in the molecular structure of the surfactant, which is positively charged. The adsorption isotherms of the dye DBlue3 onto a polyester pretreated with NCPCl at 293 K, shows that the presence of the surfactant on the surface of the fabric favors the adsorption of the dye onto the fabric. This fact shows that the pretreatment with NCPCl is a very interesting aspect in the textile industry. On the other hand, the isotherms of the adsorption of the above dye onto the polyester pretreated with a 10^?4 M solution of NCPCl, at different temperatures, shows that the amount of the dye absorbed onto the pretreated fabric increases with the increase in temperature. These behaviors can be justified by the analysis of the components of the surface free energy and zeta potential.

Electron microscopy photographs of the fabric pretreated with NCPCl before (top) and after (bottom) dyeing with DBlue3.     

Synthesis of fluorine‐containing acrylate copolymer and application as resins on dyed polyester microfiber fabric

The two resins of fluorine‐containing acrylate are synthesized by atom transfer radical polymerization. The raw materials used are hexafluorobutyl mathacrylate and dodecafluoroheptyl methacrylate. The FTIR, ¹HNMR, and ¹⁹FNMR are used to characterize copolymer structures. The application as resins on dyed polyester microfiber fabric is investigated. Shade darkening effect of the resins is discussed by color yield (K/S), rates of the color yield increase (I%), and the color differences (ΔE). The polymers containing perfluorine groups have excellent shade darkening effect on dyed polyester microfiber fabric. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Photophysical processes in poly(hexamethylene adipamide)–acid dye complexes: Energetics of nylon 66 phototendering

The mechanism of dye-sensitized photo-oxidative degradation of nylon 66 was investigated. A known phototendering dye, C.I. Acid Blue 40 (1-amino-4-(p-aminoacetanilide)-2-anthraquinone sodium sulfonate), was used for this study. Excitation and emission spectra of the dyed and undyed nylons indicated that a ground-state complex between the dye and the polyamide was formed upon dyeing. The energy level of the complex's electronic states favor triplet–triplet energy transfer from the nylon to the complex. Quenching studies show that the energy transfer occurs efficiently with a rate constant of 45.8 l. mole^?1 sec^?1. An additional energy transfer occurs between the excited free dye and the complex by either a singlet–triplet or a triplet–triplet mechanism. Kinetic analysis of the nylon-complex energy transfer suggests that the triplet energy of nylon migrates 24 to 33 Å along the amide chromophores in an exciton fashion until an energy trapping complex is reached. Energy is then transferred by an exchange mechanism. Photo-oxidative studies verify that the dye–nylon complex sensitizes the polyamide photo-oxidative degradation at its own expense without dye photobleaching.     

A heat and mass transfer study—analysis of continuous processes for the coloration of polyester fabric. I. Heat transmission to the fabric system—fabric,fiber, and dye particles

The three continuous processes (thermosol, high temperature steaming, and heat transfer printing) for the coloration of polyester and the involved equipment are briefly reviewed. A simple model for the transient heating of a body is developed, the model [eq.(22)] comprises a specific area of transfer parameter (A_s): area through which transport (of heat) takes place per unit mass of the body. This model is used in order to estimate the relative heating rates for the different geometrical approximations present in the fabric system: plate (fabric), cylinder (fiber), and sphere (dye particle). Results obtained from the more exact numerical analysis solution are used for investigating the limitations of the simple heat transfer model.     

硫化黑染涤/棉织物的两浴法染色工艺研究

本文研究了固体硫化黑染料对涤/棉织物的染色工艺,讨论了硫化黑染料和分散黑染料用量、染棉和染涤的先后顺序、是否经过前处理等工艺对涤/棉织物染色深度和染色牢度的影响,结果证明,使用两浴法用硫化黑染涤/棉的染色效果很好,并且可省去前处理工艺.     

Dyeing with polyaniline synthesis in fibers

Physicochemical aspects of dyeing with polyaniline are considered. It is shown to be possible to attain the first percolation threshold for electrically conducting polyamide fabric. An equation has been obtained for estimating the thermodynamic affinity of the dye for the fiber. Translated from Khimicheskie Volokna, No. 4, pp. 49–52, July–August, 2008.     

Study of the dyeing properties of saffron and ultrafiltrated saffron powders,as colourants for natural and synthetic fibres

There is a noticeable growing interest in the use of natural dyes in contemporary textile dyeing, motivated by the requirements imposed, in favour of environmental prosperity. The use of natural dyes reduces significantly both the energy requirements and the environmental impact of the process. In the present work natural and synthetic fibres were dyed with the dyestuff isolated from Crocus sativus L., after aqueous extraction of the dried stigmas of the plant. Additionally, part of the powder was purified by using ultrafiltration technology. The saffron extract and the ultrafiltrated saffron retentate were used to dye cotton, wool, nylon and polyester, in various depths of shade and temperatures. Both saffron and ultrafiltrated saffron successfully dyed not only the natural substrates, but also the synthetic ones, while higher dyeing temperatures produced level dyeing with all substrates used. Ultrafiltrated saffron powder produced brighter and much stronger dyeing to the original saffron powder, due to the elimination of extraction by-products. Isothermal adsorptions for both colourants were performed on all substrates in order to investigate their adsorption mechanism. It was found that saffron and ultrafiltrated saffron follow a Freundlich-type adsorption isotherm on cotton, wool and nylon which is a typical mechanism for a planar-directed dye of big molecular weight. Nernst-type adsorption was found to occur on polyester which again is typical for the adsorption of disperse dyes on polyester. Thus, saffron can be claimed as a universal dye, able to successfully dye natural and synthetic substrates.     

Cetylpyridinium chloride cationic finishing improves the dyeing and antibacterial properties of madder dyed cotton

In this work, after cationic pretreatment of cotton fabric with cetylpyridinium chloride (CPC), the compound of citric acid (CA) and succinic acid (SUA) were used as crosslinking agents to dye cotton fabrics with natural madder dye to improve the dyeing and antibacterial properties and realise the multifunctional finishing of cotton fabric. The effects of mordant dyeing, CA + SUA crosslinked dyeing, and CPC/CA + SUA crosslinked dyeing on the microstructure and properties of cotton fabrics were compared. The dyeing by the three processes occurred primarily in the amorphous zone of the fibres, and all kept the original crystalline form of the cotton. CA + SUA crosslinked dyeing and CPC/CA + SUA crosslinked dyeing increased the thermal stability of the cotton fabric. CPC/CA + SUA crosslinked dyed cotton obtained excellent dyeing results with the colour depth value (K/S) of 12.3 and rubbing fastness and washing fastness of levels 4–5, and the levelness and dye permeability were acceptable. Furthermore, the antibacterial rate against Escherichia coli and Staphylococcus aureus reached 99.99%, and the ultraviolet protection factor (UPF) reached 50+. Moreover, the wrinkle recovery angle (WRA) increased by 55% compared with raw cotton. This showed that CPC/CA + SUA crosslinked dyed cotton had excellent antibacterial, anti-ultraviolet, and anti-wrinkle performances.