Dyeing and fastness properties of polyamide fabrics using some acid‐based monoazo disperse dyes

A series of monoazo disperse dyes derived from naphthalimide containing butyric acid has been applied on polyamide fabrics. The build up and dyeing properties of these dyes such as leveling property, wash, light, perspiration for alkaline and acidic conditions, and rubbing fastnesses on polyamide fabrics have been investigated. The results showed that the applied dyes are capable of producing red to bluish red hues on polyamide fabrics. Because of the presence of both carboxylic acid and hydroxyl groups on the molecular structure of Dye 3, it showed desired and more strength in respect to other used dyes. Comparing the build up of these dyes to commercial dyes such as disperse red 60 and disperse red 73 revealed that most of the used dyes have higher build up in comparison to the commercial ones. Measurement of fastness properties of dyed samples indicated that they have good wash (4–5), rubbing (4), perspiration (4–5), and heat fastnesses (4–5) and they possess less than moderate light fastness (3–4) on polyamide fabrics. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Coloration properties and clearability of phthalimide‐derived monoazo disperse dyes containing ester groups

The coloration properties and clearability of disperse dyes prepared from phthalimide‐derived diazo components and a coupling component containing two carboxylic acid ester groups have been investigated. Members of the series featured C₂–C₄ alkyl substituents on their phthalimidyl nitrogen atom. The nature of the N‐alkyl group made no consistent difference to dye uptake on polyester. No correlation was found between percentage exhaustion and calculated solubility parameters. Wash fastness was extremely good. Comparison with analogues indicated that the diester motif was of significant extra benefit to wash fastness for phthalimide‐derived dyes, but did not increase photostability above the lower range of commercial acceptability. Clearability was compared with that of dyes lacking one or both hydrolysable structural features, as well as with that of some industrial dyes. The novel dyes exhibited a greater tendency to be solubilised, consistent with hydrolysis of their ester and/or phthalimide functionalities.     

Synthesis and spectroscopic properties of novel phthalimide‐derived monoazo disperse dyes containing ester groups

The synthesis and spectroscopic properties of monoazo dye series, whose members consist of N‐alkylphthalimide diazo components combined with a coupling component containing two ester groups, are reported. Such colourants are potentially alkali‐clearable as a consequence not only of the presence of diester functionality on the coupler, but also through use of the base‐sensitive phthalimide system. Shortening the N‐alkyl group by removing one or two methylene units from a butyl chain made little difference to absorption properties, as would be expected given the relatively minor differences in inductive character produced. Shifts in the absorption maximum of the dyes associated with dibromination of the phthalimidylazo motif and its subsequent cyanodehalogenation were in agreement with theory and literature data for related series. Diester substitution on the coupling component brought about hypsochromism and hypochromism.     

Dyeing properties of polyamide super-microfibre with disperse dyes

The dyeing properties of polyamide super-microfibres and conventional fibres dyed with disperse dyes have been studied by measuring the adsorption isotherm, the rate of dye uptake, the time of half-dyeing and the amount of equilibrium adsorption. The thermodynamic analysis shows that the adsorption isotherms of super-microfibres follow a Langmuir sorption model. The kinetic results show that super-microfibres have a faster dyeing rate and a higher equilibrium dye uptake compared to conventional fibres. This can be explained by the greater surface area and dye capacity of the super-microfibres. The wash and light fastness properties of the super-microfibres dyed with disperse dyes are lower than conventional fibres.     

Synthesis and properties of monoazo disperse dyes derived from the ethyl ester of N-benzyl-N-phenyl-β- alanine

The synthesis is described of some aminoazobenzene disperse dyes in which the ethyl ester of N-benzyl-N-phenyl-β-alanine was used as coupling component. ¹H-NMR and visible spectra of the dyes are reported and the basic fastness properties of the dyes were also determined. The lightfastness of the dyes was studied in relation to mass spectra data.     

Monoazo disperse dyes derived from mononitro-dichloro-2-aminobenzothiazoles

Nitration of dichloro-2-aminobenzothiazoles afforded the corresponding mononitro derivatives. Diazotisation of these and coupling to N-substituted anilines gave red to reddish-blue dyes for polyester. The colour of the dyes is discussed with respect to the relative orientation of the nitro and chloro substituents. Data on dyes from a trichloro- and a nitro-trichloro-2-aminobenzothiazole are also reported.     

Solubilisation kinetics of some monoazo naphthalimide disperse dyes containing butyric acid and investigation of fastness properties of the dyes on polyester

In this paper, the solubilisation kinetics of three novel monoazo disperse dyes based on naphthalimdes incorporating a butyric acid group were investigated in different conditions using spectrophotometry. All dyes showed a reasonable level of solubilisation in alkaline media. Kinetic studies of the solubilisation reaction of the dyes in alkaline media showed that the rate of solubilisation of all dyes is a pseudo first‐order reaction equation. The rate constants of the solubilisation reaction of the dyes in alkaline media indicated that dye 3 , which is prepared by the diazotisation of 4‐amino‐n‐butyric acid 1,8‐naphthalimide and coupled with N,N‐diethy‐n‐hydroxyethyllaniline, has the highest rate of reaction and dye 1 , which is prepared by the diazotisation of 4‐amino‐n‐butyric acid 1,8‐naphthalimide and coupled with N,N‐diethylaniline, has the lowest rate. The dyes were applied on polyester fabrics and their fastness properties were examined. The dyed fabrics showed a good to excellent degree of wash and rubbing fastnesses after replacing reduction clearing with alkali clearing.     

Dyeing of wool with temporarily solubilised disperse dyes

Temporarily solubilised disperse dyes derived from aminophenyl-4-(β-sulphatoethylsulphone) have been applied to wool fabric without the use of a levelling agent. By virtue of their characteristic dye structure, excellent levelling properties were observed on wool fabric. Good exhaustion, fixation and fastness test values were also obtained.     

Synthesis,spectral properties and application of novel disazo disperse dyes derived from polyester waste

Terephthalic dihydrazide was obtained through aminolytic depolymerisation of polyester bottle waste by using hydrazine hydrate. It was further reacted with 4‐aminobenzoic acid in the presence of polyphosphoric acid to obtain a cyclic compound, 4,4′‐[5,5′‐(1,4)‐phenylene)bis(1,3,4‐oxadiazole‐5,2‐diyl)dianiline, having a heterocyclic moiety. Diazotisation of this compound followed by coupling with various N,N‐disubstituted anilines afford a series of novel disazo disperse dyes. The structures of these synthesised dyes were confirmed by elemental analysis and Fourier Transform–infrared, proton nuclear magnetic resonance and mass spectroscopy. Ultraviolet–visible spectra of these azo dyes in different polar solvents showed considerable variation in the wavelength of maximum absorbance (λ_max). Application of these dyes on polyester and nylon fabrics using high‐temperature dyeing methods gave brilliant yellowish red hues with fair to moderate light fastness and very good to excellent wash fastness and sublimation fastness.     

Monoazo dyes for polyamide derived from 4-alkylamido-2-hydroxybenzoic acids

Data on a series of 65 azo dyes derived from 4-alkylamido-2-hydroxybenzoic acids are reported. The dyes are suitable for application to polyamide fibres.Many correlations between the nature of substituents and the physical, spectroscopic or tinctorial properties of dyes were established. Correlations between structure and colour of dyed fabrics were also found.     

Relationships between the structure of nitrodiphenylamine derived monoazo acid dyes and their spectroscopic and fastness properties

Fourteen monoazo acid dyes derived from 4-nitrodiphenylamine and 2-nitrodiphenylamine have been synthesized. Relationships between the position of nitro and sulphonic groups and the wavelength of the visible absorption band and also the lightfastness on polyamide fibres have been examined. It is suggested that the colour of the dyes and their lightfastness depend on the possibility of formation of intramolecular hydrogen bonding. The existence of such bonding was shown by the IR and UV-vis spectra of the investigated dyes and model derivatives of diphenylamine.     

Dyeing polypropylene fiber with disperse dyes using quaternary ammonium salts

The results of studying the effect of quaternary ammonium salts in colorimetric coloration characteristics and thermodynamic parameters of the process of dyeing polypropylene fiber with disperse dyes are presented.     

Dyeing as-spun polypropylene fibres with disperse dyes using periodic technology

The major possibility of dyeing PP fibres medium hues with disperse dyes using periodic technology was demonstrated. It was found that dyeing as-spun PP fibres ensures diffusion of the dye inside the fibre material. Use of Neonol AF 9/6 nonionogenic wetting agent during dyeing increases the amount of dye sorbed by PP fibre material. Translated from Khimicheskie Volokna, No. 1, pp. 24-26, January-February, 2008.     

Synthesis of disperse dyes derived from 1-Cyano-2-substituted-3-azabenzanthrones

Several disperse dyes have been synthesized by reaction of 6-chloro-1-cyano-2-substituted-3-azabenzanthrones by Ullmann reaction with various amines. The dyes thus obtained have been examined for their absorption characteristics and their dyeing behaviour on polyester.     

Dyeing of polyester using micro-encapsulated disperse dyes in the absence of auxiliaries

Polyurea microcapsules were prepared in this study, using disperse dye as the core material and diphenylmethane-4,4'-diisocyanate as the wall-former. Microencapsulated disperse dyes have been characterised in terms of their thermal properties, average particle size and size distribution, morphological structure and composition. Polyester fabric was dyed with microencapsulated CI Disperse Blue 56 using a high temperature dyeing process without dispersing agents, penetrating agents, levelling agents or other auxiliaries. The quality of the polyester fabric dyed in this manner – without reduction clearing – was at least as good as that dyed traditionally after washing and reduction clearing. After separating off the polyurea microcapsules, the dyebath was virtually colourless and was shown to be suitable for reuse.     

Crystallographic study of two monoazo disperse dyes with a D–π–A system

Two azo disperse dyes, 2,6‐dichoro‐4‐nitro‐4′,4′‐N‐cyanoethyl‐N‐benzyl‐azobenzene ( D1 ) and 3‐(3‐methyl‐4‐N‐ethyl‐N‐benzyl‐phenyldiazenyl)‐5‐nitro‐2,1‐benzisothiazole ( D2 ), were synthesised and characterised. The crystal morphologies and single crystal structures were measured. The various packing and supramolecular interactions were described. D1 formed stellate crystals. The two benzene rings bilateral to the azo unit were not coplanar. Their dihedral angle was 75.72°. They were linked by the azo unit and were twisted. The coupling‐component N‐substituted benzyl and benzene rings were not coplanar. The chemical structure was not the typical azo structure. A dimeric packing mode was formed between adjacent molecules in a head‐to‐head and tail‐to‐tail manner. One molecule was inserted between two dimeric molecules in a head‐to‐tail manner. D2 formed globe crystals. The isothiazole and benzene rings of the azo unit were coplanar, with the typical π–π conjugated structure. The benzene rings of the azo unit and the coupling‐component N‐substituted benzyl were vertical. Their torsion angle was 179.9°.     

A study of some monoazo dyes containing the 1H-benzotriazole nucleus

Dyes containing the benzotriazole nucleus with various groups imparting a chelating property to the dye molecules have been synthesised. The dyes showed interesting properties for application to cotton and polyester.     

Decolorisation of a monoazo disperse dye with Candida tropicalis

Decolorisation of a heterocyclic monoazo disperse dye by the yeast species Candida tropicalis growing in mineral salt medium has been investigated. The effects of nutritional as well as environmental factors on the decolorisation efficiency were studied. Though Candida tropicalis displayed good growth in aerobic conditions, the colour removal was best under anoxic conditions. The degradation products of the decolorisation experiments under aerobic, as well as anoxic, conditions have also been identified.     

Novel azo dyes derived from phthalimide. Part 2: Dyeing properties and colour fastness on polyester fibres†

The coloration and fastness properties of 18 carbocyclic monoazo disperse dyes bearing a phthalimide ring fused to the aromatic ring of their diazo components have been investigated. In each case, the phthalimidyl nitrogen atom was substituted with either a butyl, sec‐butyl or isopropyl group, while the adjoined phenyl ring bore a substitution pattern typical of commercial colorants. Dye uptake and build‐up onto both conventional and microfibre polyester through exhaustion dyeing were examined: while the expected tendency of greater exhaustion on microfibre was noted, there were few clear trends with respect to dye structure. The nature of the N‐alkyl group made no consistent difference to dye uptake. Attempts to explain the observed percentage exhaustion values by mapping them to calculated partition coefficient or solubility parameter values were unsuccessful. Wash fastness tended to be best for blue dicyano‐substituted derivatives, which may be as a result in part of these substituents promoting hydrolysis of the adjacent phthalimide ring to give more soluble phthalate species. In contrast, the dicyano dyes had relatively poor photostability compared with their unsubstituted analogues.