Synthesis and evaluation of a series of novel monoazo disperse dyes derived from N-carboxylic acid-1,8-naphthalimide on poly(ethylene terphthalate)

A series of novel monoazo disperse dyes based on N-carboxylic acid-1,8-naphthalimides have been synthesized via 4-(4-amino-1,8-naphthalimido) butanoic acid as diazo components and various couplers. The synthesized dyes were characterized with elemental analysis, differential scanning colorimetry, Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and UV-visible spectroscopic techniques. The molar extinction coefficient, wavelength maxima, and solvatochromism effect were obtained using chloroform, acetone, and N,N-dimethyl formamide as solvent. The results showed that the synthesized dyes had molar extinction coefficient of 20908 to 38939 l mol⁻¹ cm⁻¹, wavelength maxima of 409–549 nm, and positive solvatochromism by changing solvent from chloroform to N,N-dimethyl formamide. The synthesized dyes were applied on poly(ethylene terephthalate) using high temperature method. Dyes 1 and 2 showed high build-up properties on poly(ethylene terephthalate), whereas dyes 3 and 4 offered medium build-up. All the dyes offered excellent heat fastness, good wash and rubbing fastnesses on poly(ethylene terephthalate) fabrics. The hydrolysis of the synthesized dyes in alkali media indicated that the presence of a carboxylic acid group within the dye molecules provides alkali-clearable potential.     

Relation between chemical structure of yellow disperse dyes and their lightfastness

Five yellow disperse dyes were synthesized and their dyeing, fastness and photodegradation behaviors were investigated. It was found that dyes derived from phenylindole and N-alkylaminobenzene showed dye uptake directly proportional to the dye concentration, but the build-up of dyes derived from carbazole and pyridone were not good. The wavelength at maximum absorption, molar extinction coefficient, and the tendency to the photodegradation were strongly dependent on the electron donating ability of the coupling component. The dye, whose coupling component was phenylindole, possessed the excellent dyeing properties and the high degree of lightfastness. UVA had an effect on the inhibition of the photodegradation especially for the easily photodegradable dyes.     

Synthesis of cationized anthraquinone dyes and their dyeing properties for meta-aramid fiber

Due to compact structure of meta-aramid fiber caused by the intermolecular hydrogen bondings of amide groups, the degree of crystallinity increased, thus its poor dyeing properties arises. Among commercial dyes used in many previous researches, the basic dyes showed comparatively higher exhaustion yields as comparing to those of disperse dyes and acid dyes. The anthraquinone moiety was adopted for good performances of light fastness on meta-aramid fiber. In this study, eight of anthraquinone dye was synthesized. The three of them were obtained from chloro-anthraquinone, by Ullmann reactions with the corresponding heterocylic residues such as morpholine and one of them was obtained from lueco quinizarine by condensation with the corresponding heterocylic residues. The others were prepared by quaternization from dyes above. The synthesized disperse and cationic dyes were dyed on meta-aramid fibers and investigated for their build-up dyeing properties and wash fastness.     

Coloration of poly(lactic acid) with disperse dyes. 1. Comparison to poly(ethylene terephthalate) of dyeability, shade and fastness

The dyeability of poly(lactic acid) [PLA] with a range of commercial disperse dye was examined and compared to that of poly(ethylene terephthalate) [PET] in addition to the colour and fastness of the resultant dyeings. A screening exercise in which twenty dyes of differing energy types and chemical classes were applied to PLA revealed a substantial variation between the dyes in terms of dye uptake (12–88 % at 4 %o.w.f.). Nine dyes exhausted above 70 % and were selected for further study, which involved comparison of shade and fastness of PLA dyeings with those of the corresponding PET dyeings. Differences in shade depended on hue while wet fastness of each of the PLA dyeings was either the same or 0.5–1.0 point lower than its PET counterpart. In all but one case, dye photostability in PLA was found to be very similar to that in PET. Dye build-up profiles on PLA were also investigated and from these results mixtures of compatible dyes identified.     

Synthesis,characterization and ultrafiltration of reactive dyes. Application by exhaustion and/or ink-jet printing. IV.

Three new bis azo reactive dyes of different metallic salts (Na, K, Li) were synthesized. The synthesis was obtained by diazotization of 4-amino-2:5 di methoxy phenylene-beta hydroxyl ethyl sulphone sulphate ester and coupling with 1-amino-8-hydroxynaphthalene-3,6-disulfonic acid (H-acid) (moles ratio 2:1). The dyes were purified-concentrated by ultrafiltration technology, characterized and applied on cotton, wool and nylon 6,6 fabric by exhaustion (dyeing) and by ink-jet printing. Fastness properties of the dyeings were measured. Wash fastness was investigated according to international standard methods and was found to be very good to excellent in all cases, while light fastness values were medium to low. Ink-jet ink formulations were prepared using the ultra filtrated reactive blue dyes UF RB(a-c) and their properties pH, conductivity, surface tension and viscosity were monitored over a period of 90 days. The inks were used to print digitally cotton and nylon 6,6 samples and wash- and light fastness properties of the prints were measured. Wash fastness properties were excellent while light fastness values are low Colour measurements of the dyeings and prints were conducted.     

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.     

Synthesis and properties of alkali-clearable azo disperse dyes containing a carboxylic ethyl ester group

Three alkali-clearable azo disperse dyes containing a carboxylic ethyl ester group (D1-D3) were readily synthesized using three different synthetic strategies. D1 was prepared from a carboxylic acid-containing dye by esterification with ethanol. D2 was prepared from a carboxylic ester-containing dye by transesterification with ethanol. D3 was prepared from a cyano group-containing dye by alcoholysis with ethanol and water. The molecular structures of the dyes were characterized by FTIR, mass spectrometry, ¹H NMR, ¹³C NMR, and elemental analysis. The synthesized dyes and the control dyes were used to dye poly(ethylene terephthalate) fabric, and their washing and rubbing fastness properties following different after-treatment methods (reduction clearing and alkali clearing) were examined and compared. The carboxylic ethyl ester-containing disperse dyes show good alkali clearing ability on poly(ethylene terephthalate) fabric and cause fewer environmental issues due to the absence of reductants, no production of aromatic amines with high toxicity and carcinogenicity, as well as the low toxicity of the dye hydrolysate ethanol.     

Salt free reactive dyeing of cationized cotton

In this study 3-chloro-2-hydroxypropyltrimethylammonium chloride was used as a cationic agent to cationize cotton fabric by a pad-batch process. The cationized cotton samples were dyed with different reactive dyes containing various reactive groups. The dyeability of the cationized cotton samples with reactive dyes without salt was significantly improved due to an increase in the ionic attraction between the dye and cationized cotton. The results showed that the wash and dry rubbing fastness of the cationized cotton dyed with different reactive dyes are similar to those of the untreated cotton. However, the light fastness of some of the cationized fabric samples was improved.     

Dyeing properties of novel azo disperse dyes derived from phthalimide and color fastness on poly(lactic acid) fiber

The coloration of poly(lactic acid) (PLA) fiber with 18 carbocyclic monoazo disperse dyes bearing a hydrolyzable phthalimide ring fused to the aromatic ring of their diazo components has been investigated. The phthalimidyl nitrogen atom was substituted with either a n-butyl, sec-butyl, or isopropyl group, while the adjoining phenyl ring bore a substitution pattern typical of commercial colorants. There was a broad correlation between percentage dye exhaustion onto PLA and that onto polyester (PET) fiber, although significant differences in certain instances were apparent with no clear trends regarding dye structure. Attempts to explain the observed percentage exhaustion values by mapping them to calculated partition coefficient or solubility parameter values were unsuccessful. Wash fastness was relatively good compared to that of some conventional disperse dyes applied to PLA. As was found to be the case with PET, the wash fastness of dyes on PLA tended to be highest when their diazo ring was substituted with electron acceptors.     

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.     

Acrylamide-assisted Photografting of Bisacrylamide Dyes onto Cotton

Dibromopropionamide groups of C.I. Reactive Red 136 were dehydrobrominated to obtain bisbromoacrylamide groups. Photografting yield of the modified dyes onto cotton increased with the addition of acrylamide comonomer, presumably reducing the steric hindrance between the dyes with bulky chromophores. The acrylamide-assisted grafting was more prominent with increasing degree of the functionality. The optimum grafting was obtained with 2.5 molar ratio AAm and 7 % photoinitiator with respect to 0.03 mol/l dye under a UV energy of 25 J/cm². The grafting yield and K/S of the grafted cotton with C.I. Reactive Red 83 was lower than that with the modified Red 136 at the same degree of functionality 2.0, probably because the relatively larger chromophore of the Red 83. In addition, the washing, rubbing and light fastness of the grafted cotton fabrics with the modified Red 136 were higher than the adsorption-based conventional dyeing, which was more pronounced as the degree of functionality increased.     

Dyeing properties of nylon 66 nano fiber with high molecular mass acid dyes

Research and development of nano fiber products is very active over the world. Physical characteristics and dyeing properties of nylon 66 nano fiber were investigated in this study. X-ray diffraction, DSC, analysis of amino end group, and water absorption were performed to get information concerning physical properties of nano fiber. Nylon 66 nano fiber was dyed with high molecular mass acid dyes. Effects of dyeing temperature, pH of dyeing solution, and concentration of acid dyes on dyeing properties such as rate of dyeing and the extent of exhaustion, were examined and compared to those of regular fiber. It was found that nano fiber adsorbed acid dyes at lower temperature, got rapidly dyed, and its extents of exhaustion at specific dyeing temperature were higher than regular fiber. It was also observed that nano fiber could adsorb a large amount of acid dye without a significant loss in the extent of exhaustion. Washing fastness of the dyed nano fiber was lower by 1/2∼1 grade, light fastness by 1 grade than the dyed regular fiber.     

Coloration of poly(lactic acid) with disperse dyes. II. Dyeing characteristics and color fastness

In Part 1 of this study, the dyeability, color shade, wash, light fastness and compatibility of homogeneous disperse dyes on PLA fabric and PET fabric were reported. The present paper (Part 2) focuses on the application of commercial disperse dyes to PLA fabric. Specific areas of investigation are the coloration properties of dyes originally intended for the production of high lightfastness polyester fabrics or for application to cellulose diacetate. The compatibility of the eight members of the dye set was investigated. In terms of lightfastness, the ratings were higher than that of conventional disperse dyes. In addition, the use of dye combinations to achieve synergistic uptake on PLA was explored leading to the pronounced synergism with a mixture of CI Disperse Blue 374 and 284.     

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.     

Dispersant-free dyeing of poly(lactic acid) knitted fabric with temporarily solubilized azo disperse dyes

Poly(lactic acid) (PLA) is known for environmentally friendly material as it is derived from annually renewable crops and biodegradable. Dispersant-free dyeing of PLA fabric with three temporarily solubilized azo disperse dyes which contain β-sulfatoethylsulfonyl group was investigated and their dyeing and fastness properties were compared with those of commercial disperse dyes. The temporarily solubilized azo disperse dyes were successfully applied to PLA fabric without the use of dispersant. The color yield on PLA fabric was dependent on dyebath pH and dyeing temperature as well. The optimum results were obtained at pH 7-8 and 110 °C. The dyes showed markedly higher color yield on PLA fabric when compared to commercial disperse dyes. Wash fastness was very poor to poor but light fastness was good. The COD levels of the dyeing effluent from the temporarily solubilized disperse dyes were considerably lower than those from commercial disperse dyes.     

Synthesis of hydrophobic anthraquinoid magenta dyes having linear alkyl substituents

A new series of magenta dyes having different length of alkyl substituents was synthesized to dye unmodified polypropylene (PP) and ultra-high molecular weight polyethylene (UHMWPE) fiber. It could be concluded that the affinity of the dyes onto unmodified PP and UHMWPE fibers was increased with the increase of the length of alkyl substituents. The optimum length of alkyl group was determined as the longest dodecyl-substituted dye in this study. Their absorption spectra appeared almost the same at visible range, which meant that the length of alkyl substituents did not affect the color appearance of the dyes. The color fastness properties of the dyeings to washing, rubbing and light were good enough for commercialization.     

One-Bath Union Dyeing of Wool/Acrylic Blend Fabric with Cationic Reactive Dyes Based on Azobenzene

Three unreported cationic reactive dyes based on azobenzene were synthesized using a novel synthetic route. Synthesized dyestuffs containing three primary color dyes were characterized by FTIR, H-NMR, LC-MS, Element Analysis and UV-vis spectroscopic techniques. The absorption spectra of dyes were measured in three solvents with different polarities. The dyeing and color fastness properties of three cationic reactive dyes on wool, acrylic and wool/acrylic blend fabrics were determined. The optimum pH for wool and acrylic fabrics were 6 and 5, respectively. Effect of temperature, time on dyeing properties and color fastness properties on wool fabric showed the same tendency with acrylic fabric. The K/S value of wool fabric dyed with three dyes was similar to that of acrylic fabric when both fabrics were dyed simultaneously in the same dyebath using low dye concentration. Wool/acrylic blend fabric dyed with three cationic reactive dyes using onebath one-step method achieved good union dyeing property and excellent color fastness.     

Dyeing properties of nylon,PET, and N/P mixture fabric with reactive-disperse dyes having a sulfatoethylsulfone group

The dyeing and color fastness properties of two reactive-disperse dyes containing a sulfatoethylsulfone group on nylon, PET and N/P mixture fabrics were examined. The rate of dyeing on nylon fabric was greatly dependent upon dye bath pH. The final dye uptakes at all pH, however, were as high as 97 %. Color strength of the dyed nylon fabric linearly increased up to 0.5 %owf and then slowed down over 1 %owf dyeing. Washing and rubbing fastness of the dyed nylon fabric were excellent, but grade of light fastness was moderate. Dyeability of the reactive-disperse dyes on PET fabric was not much affected by pH, and K/S values of PET fabric dyed at pH 5–8 were lower than those of nylon fabric at all pH examined. Buildup and color fastnesses properties on PET fabric showed the same tendency with nylon fabric. The rate of dyeing of the reactive-disperse dyes on nylon fabric was faster than on PET fabric when both fabrics were dyed simultaneously in the same dye pot, resulting in higher color strength of nylon than PET. The reactive-disperse dyes were found to be adequate to the one-bath, one-step dyeing of N/P mixture fabric when applied at pH 5 and 120 °C.     

Coloration of ultra high molecular weight polyethylene fibers using alkyl-substituted monoazo yellow and red dyes

UHMWPE fibers were dyed with yellow and red dyes having different length of alkyl substituents on monoazo chromophores. The dyeability was investigated at various conditions and fastness of the dyeings was examined. As the length of alkyl substituents increased, the dyeability toward UHMWPE fibers tends to be improved gradually up to propyl or butyl groups and then decreased for the longer alkyl substituents. Color strength of the fabrics was increased with the increase of dyeing temperature from 100 to 130 °C. From the dyeing rate, equilibrium dyeing at 130 °C was achieved at 2～3 h. The color fastnesses to washing, rubbing, and light of the dyeings were good showing higher than 4 ratings except for light fastness of the red dye.     

Dyeing performance of disperse dyes based on 2-aminothiazole for cellulose triacetate and nylon fibers

A series of monoazo disperse dyes based on 2-amino-4-phenylthiazole was prepared using variousN,N-dialkylaniline derivatives as the coupling component. The dyes were characterized by IR spectral studies, visible absorption spectroscopy and elemental analysis. The dyeing performance of these dyes was assessed on cellulose triacetate and nylon fibers. These dyes were found to give a wide range of colour shades varying from bright red to royal blue with very good depth, brightness and levelness on fibers. The dyed fibers showed good to very good light fastness and very good to excellent fastness to washing, perspiration, rubbing and sublimation. The dyebath exhaustion and fixation on the fibers were found to be very good.