The roles of elevated temperature and carriers in the dyeing of polyester fibres using disperse dyes: Part 1 fundamental aspects

This review concerns the application of disperse dyes to poly(ethylene terephthalate) (PET) fibres using aqueous immersion dyeing processes and the roles of both elevated dyeing temperatures and carriers in such dyeing systems. This part of the paper presents a review of the fundamental properties and characteristics of PET fibres, disperse dyes and dyeing accelerants. In the next part of the paper, the various theories and concepts that have been proposed to explain the promotional effects imparted by elevated dyeing temperatures and carriers to disperse dye uptake on PET and other types of fibre, are reviewed and analysed, from the viewpoints of the essential physico-chemical aspects of both the aqueous disperse dye/PET and disperse dye/carrier/PET systems. Later parts of the paper will present a mechanistic model of the disperse dye adsorption process based on dye solubility as well as a novel plasticisation model of dye diffusion.     

The solubility parameter concept applied to disperse dyeing of polymers

The solubility parameter concept offers a logical link between the theory of solutions and of nonionic (disperse) dyeing. An attempt has been made to apply the concept to correlate the solubility of several disperse dyes in secondary cellulose acetate, cellulose triacetate, and polypropylene with the calculated solubility parameters of both the polymers and the dyes. When the dyes are applied on hydrophilic polymers from an aqueous dispersion, the correlation between the solubility parameter concept and the dye solubility is not close. One of the reasons for this may be the fact that dyeing of the fibers is, in fact, not a solution in the dry fibers, but consists essentially either in displacement of water molecules from the water swollen fibers and/or, perhaps, in additional swelling by the dye. Consideration of this fact and also correcting for the contribution of hydrogen bonding and dipole interactions to the cohesive energy density brings the disperse dye solubility data into a better agreement with the concept. The concept should be applicable without complications to the dyeing of nonpreswollen fibers, such as polypropylene from aqueous dispersion, or any fiber by the Thermosol process and particularly to dyeing from the vapor phase. The few data available appear to support this view.     

Vinyl graft polymerization-induced modification of some properties of poly(ethylene terephthalate) fabric

Polymerization of glycidyl methacrylate (GMA), methyl methacrylate (MMA), and acrylic acid (AA)/styrene (St) mixtures with poly(ethylene terephthalate) (PET) fabric to different polymer add-ons was performed. Moisture regain, dyeability, and soiling properties of the modified PET were examined. It was found that introduction of poly(GMA) in PET structure brings about (a) improved moisture regain, (b) enhanced dyeing with disperse dyes, (c) affinity and possible dyeing with acid, direct, and reactive dyes, (d) improved aqueous and nonaqueous oily soil resistance, and (e) decreased ease of soil removal. The magnitude of moisture regain, dyeability, and soiling properties are dependent upon the percent of polymer add-on. Polymerization of MMA with PET improved the dyeability of the latter with the disperse dye as well as its resistance to nonaqueous oily soil while decreasing the resistance to aqueous soiling and ease of both aqueous and nonaqueous soil removal. In the case of PET polymerized with poly(AA/St), there was a considerable enhancement in moisture regain, dyeing with the disperse dye, and resistance to aqueous and non-aqueous oily soiling. On the other hand, both aqueous and nonaqueous soil characteristics of PET were imparted by polymerization of the latter with AA/St mixtures.     

Compatibility of a disperse dye mixture in supercritical carbon dioxide dyeing

The compatibility of three disperse dyes, CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, which are commonly used as a trichromatic combination for conventional dyeing, was studied in supercritical carbon dioxide dyeing. Both the dyeing rate and the build‐up of the selected dyes were measured. Experimental results showed that they were quite compatible. The dyeings of a binary combination (CI Disperse Orange 30 and CI Disperse Blue 79, mass ratio 1:1) and a ternary combination (CI Disperse Orange 30, CI Disperse Red 167 and CI Disperse Blue 79, mass ratio 1:1:1) at different dye concentrations showed an on‐tone uptake and presented the same metric hue angles. This proved that the selected dyes could form a useful trichromatic combination in supercritical carbon dioxide dyeing. Furthermore, the uptake and exhaustion of the single dyes in supercritical carbon dioxide dyeing were similar to those in aqueous dyeing, implying that the dyeing media play only a minor role in the dyeing of polyester fibres with disperse dyes.     

Application of sodium benzoyl thiosulphate from aqueous solution to wool and its effect on substantivity of disperse dyes. Part 1: synthesis and characterisation of sodium benzoyl thiosulphate

The introduction of bulky aryl residues into wool fibres not only enhances their disperse dyeability but also improves their settability, shrink resistance and imparts easy‐care properties. It would be highly desirable for colourists to achieve such effects when dyeing or printing wool from an aqueous solution as wool/polyester blend fabrics could be dyed and printed with the same dye; furthermore, in the case of an all‐wool fabric pretreated with such arylating systems, following dyeing or printing with disperse dyes, dye fixation can be achieved by dry heat procedures. A water‐soluble, fibre‐reactive arylating agent, sodium benzoyl thiosulphate, was therefore synthesised, characterised and its stability to hydrolysis in aqueous media was examined.     

低聚物对聚酯织物分散染料染色废液COD_(Cr)的影响

采用原位聚合法在不同芯壁比条件下对纯分散染料进行微胶囊化,将其对溶剂萃取过低聚物的TTT及PET织物进行染色,采用紫外分光光度法测定染色废液CODCr值,并与相应的商品分散染料染色废液CODCr值进行比较.结果表明,低聚物的存在将增大PTT及PET织物染色废液的CODCr值;对于相同分散染料,芯壁比为1:2的微胶囊染色废液CODCr值大于芯壁比为1:4的微胶囊染色废液CODCr值;微胶囊分散染料染色废液CODCr值远低于相应商品分散染料的染色废液CODCr值.     

The Diffusion of Disperse Dyes in Polymer Films

The diffusion of disperse dyes in various polymer films has been studied by a microdensitometric technique. The films were dyed in aqueous dye dispersions, in presence and in absence of dyeing accelerants, and in solutions of dye in organic solvents. Dyeing of appropriately pretreated films conformed to the model of Fickian sorption, whereas dyeing of polymer films in the presence of dyeing accelerants showed in some instances marked deviations from this model. These results are discussed in terms of modern theories of diffusion.     

VIS absorption spectrophotometry of disperse dyes

In the investigations of the dyeing processes, the low solubility of disperse dyes in water represents a practical problem for the determination of dye concentration in dyebaths and waste waters. Therefore the use of an organic solvent which, dissolves disperse dyes, is recommended in visible spectrophotometry of disperse dyes. Three organic solvents (ethanol, N,N-dimethylformamide, acetone) and two disperse dyes, the disazo dye C.I. Disperse Orange 29 and the anthraquinone dye C.I. Disperse Blue 56, were used for spectroscopic analysis in this present work. The absorbance of aqueous dye dispersions and various organic solvent dye solutions was measured to evaluate the effect of the solvent on the shape and intensity of the absorption spectra and on the wavelength shift of maximum absorption. The validity of Beer–Lambert’s law in each system was ascertained. A suggestion is made how VIS absorption spectrophotometry can be used to determine the dye concentration in disperse dyebaths. The addition of organic solvent to the dyebath leads to dye dissolution, and the Beer-Lambert’s law is then fulfilled. The optimum ratio between the dyebath dispersion and the organic solvents for the dyes investigated is also determined.     

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 3 physical properties of water and water-derived fibre properties

In the absence of published information regarding the temperature dependency of water-derived poly(ethylene terephthalate) fibre properties, the findings reported for the thermally regulated interactions between water and 100% amorphous poly(ethylene terephthalate) materials were interpreted from the perspective of the amorphous domains that reside within semi-crystalline polyester textile fibres. This analysis suggests that the pronounced temperature dependent uptake of a commercial grade disperse dye on poly(ethylene terephthalate) fabric achieved during an aqueous dyeing process at temperatures between 30 and 130°C is the likely result of the combination of three separate, but inherently inter-related, thermally activated phenomena, namely, polymer structural relaxation, in which polymer glass transition assumes a dominant role, dissolution of disperse dye in the aqueous dyebath, as well as various water–fibre interactions, in the guise of water sorption, water molecule diffusivity, water-induced swelling and water-induced plasticisation. Although thermally regulated macromolecular relaxation processes adopt the principal role in dye uptake, temperature dependent dye solubility and water-derived fibre properties nevertheless likely provide crucially important supportive roles.     

Effect of microencapsulation on dyeing behaviors of disperse dyes without auxiliary solubilization

Microencapsulated disperse dye can be used to dye hydrophobic fabric in the absence of auxiliaries and without reduction clearing. However, little available information for dyeing practice is provided with respect to the effect of microencapsulation on the dyeing behaviors of disperse dyes. In this research, disperse dyes were microencapsulated under different conditions. The dyeing behaviors and dyeing kinetic parameters of microencapsulated disperse dye on PET fiber, e.g., dyeing curves, build up properties, equilibrium adsorption capacity C_∞, dyeing rate constant K, half dyeing time t_1/2, and diffusion coefficient D were investigated without auxiliary solubilization and compared with those of commercial disperse dyes with auxiliary solubilization. The results show that the dyeing behaviors of disperse dye are influenced greatly by microencapsulation. The diffusion of disperse dyes from microcapsule onto fibers can be adjusted by the reactivity of shell materials and mass ratios of core to shell. The disparity of diffusibility between two disperse dyes can be reduced by microencapsulation. In addition, the microencapsulation improves the utilization of disperse dyes due to no auxiliary solubilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The effect of dyes and dyeing on the mechanical properties of polymeric materials

The effect of reactive and disperse dyes and dyeing on the mechanical properties of cotton and polyester fibers, respectively, has been studied. It is observed that reactive dye (Procion Brilliant Red MX-2B) and disperse dye (Dispersol Red B-2B) caused a decrease in the tensile strength of the fiber which was often accompained by a decrease in the extensibility and general improvement in the tensile stiffness of the fibers. A linear relationship exists between percent disperse dye on the fiber and the square root of time of dyeing for poly(ethylene terephthalate) fibers in the initial region of dye uptake.     

聚对苯二甲酸丙二酯纤维的染色性能

根据Shell公司和Dystar公司的研究,用Optidye系统从分散染料吸附与上染率、染色温度、pH值、匀染性及染色牢度等方面解析了聚对苯二甲酸丙二酯(PTT)纤维的染色性能。PTT纤维在100℃就可染到深色,在60～80℃和90～100℃有两个吸附速度较快区域;PTT纤维属易染型纤维,在最高温度染保持30～40min即可。高温型分散染料在120℃染色,常压100℃染色无需pH值调节。分散染料染色牢度(洗涤、摩擦及耐光)非常好。     

芳纶1313的超高温高压染色研究

本文采用超高温高压法对芳纶1313进行染色,分别研究了染料种类和染色温度对芳纶1313纱线染色日晒牢度、K/S值及染透性等方面影响,结果发现,分散染料所染纱线的各项染色性能都比阳离子染料和还原染料好;随染色温度升高,日晒牢度、纤维表面颜色深度及其纤维染透性都得到了不同程度的改善,而纱线的断裂强度随染色温度的升高变化不大。     

Dyeing of nylon 6 fabric with a bifunctional sulphatoethylsulphone reactive disperse dye

A bifunctional reactive disperse dye containing two temporarily anionic sulphatoethylsulphone groups was synthesised and applied to nylon 6 fabric by exhaust dyeing at a variety of pH levels and temperatures. A monofunctional reactive disperse dye containing one temporarily anionic sulphatoethylsulphone group was also synthesised, and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and total fixation yield under alkaline conditions. The results also indicate that the introduction of two temporarily anionic sulphatoethylsulphone groups of the bifunctional dye gave an enhancement in dyeing performance compared with that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Dyeing of nylon 6 fabric with a new bifunctional vinyl sulphone reactive disperse dye

A new bifunctional reactive disperse dye containing a temporarily anionic sulphatoethylsulphone and a nonionic disulphide bis(ethylsulphone) groups was synthesised and applied to nylon 6 fabric by the exhaust dyeing at a variety of pH and temperature conditions. A monofunctional reactive disperse dye containing only nonionic disulphide bis(ethylsulphone) group was also synthesised and its dyeing behaviour was compared with the bifunctional dye. The bifunctional reactive disperse dye exhibited high exhaustion and fixation values at pH 6 and 120 °C. The results also indicate that the combination of temporarily anionic and nonionic reactive groups of the bifunctional dye provided great enhancement in dyeing performance compared to that of the monofunctional dye. The dyes also showed very good levelling and fastness properties on nylon 6 fabric.     

Studies in dyeing. I. Effect of crystal modification of disperse dyes on their dyeing behavior

Three commerical disperse dyes and a laboratory-synthesized disperse azo dye were converted to different crystal forms. These were characterized by melting point, x-ray diffractograms, and their dyeing behavior on polyester fibers. The different crystal modifications of the same dye were shown to dye polyester fibers (but not polyamide fibers) at different rates and to different fiber saturation values. An attempt has been made to explain these differences based on a thermodynamic approach. An attempt is made to apply the concept of crystal modification of disperse dyes to some of the earlier studies done on dyeing and printing of disperse dyes on polyester and secondary cellulose acetate substrates reported in the literature.     

染色条件对对位芳纶染色性能影响研究

进行了适用于对位芳纶染色的分散染料及染色载体品种的筛选,研究了染色条件对对位芳纶染色性能的影响。结果表明,分散蓝B_1、B_2、B_3及分散红R_1、R_2等染料在C_1及C_2等载体助染下,染色效果较好;合适的载体用量、染色温度、染色时间、染料浓度、染液pH值、染液浴比等染色条件对提高对位芳纶染色效果明显。     

提高深色羊绒摩擦牢度的研讨

深色羊绒摩擦牢度与纤维本身所合“杂质”有关，染色前，用合有替合剂和表面活性剂的水溶液进行前处理，用媒介染料染羊毛时添加分散替合剂，用Lanasol活性染料染羊毛时添加由异丁醇、苄醇、脂肪叔胺聚氧乙烯改组成的匀染剂可以提高摩擦牢度。探讨了染料的化学结构、染料的纯度、染料的提升力、染色后处理与干、湿摩擦牢度的关系。     

Study of physico-chemical surface treatments on dyeing properties of polyamides. Part 2: Effect of UV excimer laser irradiation

Polyamide (nylon 6) fabrics were irradiated with a 193 nm argon fluoride excimer laser and the effects on the dyeing properties of the fabrics were studied. Chemical analysis indicated that carbonisation occurred in the laser-irradiated samples. The laser treatment breaks the long chain molecules of nylon, increasing the number of amine end-groups which change the dyeing properties of acid and disperse dyes. The results suggest that laser treatment could be used to improve the dyeing properties of nylon fabric with a disperse dye.     

Waterless dyeing of polylactic acid with disperse dyes using decamethylcyclopentasiloxane as medium

Polylactic acid (PLA) fibre as a new generation of eco-friendly polyester fibre is expected to substitute polyethylene terephthalate (PET) fibre to be an important textile fibre raw material. However, there exist severe strength loss and light dyeing colour by the traditional water bath dyeing method, which seriously affect the promotion and application of PLA fibre in the textile fields. Therefore, it is necessary to study waterless dyeing method for PLA. Decamethylcyclopentasiloxane (D5) possesses excellent physical and chemical properties with the characteristics of odourless, non-flammable, and stable to various chemicals, which has been studied to be used as a waterless dyeing medium for PET fabric. In this study, D5 was selected as the medium to study the waterless dyeing process and properties for PLA. The effects of disperse dye dosage, dyeing temperature, dyeing time and liquor ratio on the dyeing properties of PLA fabric were investigated. The results showed that the optimal dyeing process conditions were as follows: the dye dosage was 4%, dyeing temperature and time were 120°C and 40 min, respectively, and the liquor ratio was 1:10. Then PLA was dyed by three different colour disperse dyes using the optimal process which were compared with the traditional water bath. The results showed that the properties of dyed PLA fabrics with D5 could reach the dyeing effect of the traditional water bath method, while causing less influence on its mechanical property. Therefore, this research proved that D5 can be used as a dyeing medium for PLA fabric to substitute the traditional water bath dyeing.