Dyeing of N-modified viscose rayon fibres with acid and metal-complex dyes

Viscose rayon N -modified by the incorporation of polydiallyldimethyl ammonium chloride gave good dye exhaustion and colour yield on dyeing with acid or metal complex dyes. The amount of additive present in the fibre was assessed from its nitrogen content, and percentage exhaustion was found to increase with increasing quantity of additive. Changes in hue, in addition to an increase in the light fastness of deeper shades, are attributed to aggregation of dye within the fibre. The light fastness of metal complex dyes on N -modified fibre was very good but acid dyes gave poor results. Wash fastness was improved after treating with a dye fixing agent.     

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.     

Dyeing of polyamide—wool fibre blend with acid dyes using α-cyclodextrin

The colors of polyamide fibre obtained in dyeing with α-cyclodextrin (CD) additive are uniform and saturated. This effect is also obtained on wool fibre and wool—polyamide fibre blend. It was found that the dyeability of the samples with α-CD is much higher than for samples without the additive with an increase in the temperature. In spectrophotometric determination of complexation in the dye—α-CD aqueous system, it was found that the dyeability of the samples was highest in a 1:1 ratio than with the standard dyeing method. α-CD thus acts as a process booster. __________ Translated from Khimicheskie Volokna, No. 3, pp. 37–39, May–June, 2007.     

Thermal properties of nylon 6 fibres grafted with acrylic monomers

Thermal Properties of methyl methacrylate (MMA), ethyl methacrylate (EMA) and n-butyl methacrylate (n-BMA) grafted onto nylon 6 fibre with various graft levels were investigated by thermogravimetric analysis (TGA) and differential thermal analysis (DTA) and the results compared with that of parent nylon 6 fibre. It was found that the initial decomposition temperatures (IDT) of the grafted samples were lower than that of the parent nylon 6 fibre. On the other hand with all the three monomers, there was an increase in overall thermal stability followed by subsequent decrease with increase in the graft level. Among the grafted samples both the IDT and IPDT (initial procedural decomposition temperature) followed the order MMA-g nylon > EMA-g nylon < n-BMA-g nylon Differential thermal analysis shows a depression in glass transition temperature (T_g) as well as in melting temperature (T_m). In the case of the MMA and EMA grafted samples, the depression is small over a wide range of graft level. In the case of the n-BMA grafted samples, the depression is higher. A wide melting range was obtained in the grafted samples. Flammability studies also showed that with an increase in the graft level as well as an increase in the alkyl chain the ease of flammability increased as expressed by limiting oxygen index (LOI) values. The possible reasons for the phenomena occurred have been discussed.     

Dyeing properties of soya fibre with reactive and acid dyes

In order to determine the most suitable type of dye for soya bean fibre, the dyeing properties of three acid dyes and three bifunctional reactive dyes were compared. Additionally, the effect of a range of reactive groups on dyeing performance were studied, including difluorochloropyrimidine, monofluorotriazine, monochlorotriazine and β-sulphatoethyl sulphone, and of these the first was found to perform best. Irrespective of reactive group, however, the main factor affecting build-up was found to be the substantivity of the dye for soya fibre. The monofunctional reactive dyes in general were found to exhibit good wash fastness.     

Dual permeation of acid dyes through nylon 6 membrane

Permeation of acid dyes in nylon 6 membrane was measured and analyzed by the dual sorption and diffusion mechanism, comprising partition and Langmuir-type modes. The results were compared with our previous work on diffusion in the same system by the film roll method. Diffusion coefficients of both dye species were found to be similar in magnitude.     

Dyeing of N-modified viscose rayon fibres with reactive dyes

Modified viscose rayon fibres were produced by incorporation of different doses of a polydiallyldimethylammonium chloride based additive in the viscose dope prior to spinning. On dyeing the modified fibres with different reactive dyes, excellent dye exhaustion and total dye fixation above 90% were obtained without the use of electrolyte and with low salt concentration. Exhaustion and total dye fixation showed an exponential relationship. The wash fastness properties of the dyed fibres were excellent and the light fastness showed a slight drop in the modified fibres. The presence of the amino groups along with low density and crystallinity of the modified fibres may be responsible for the enhanced dyeability.     

Dyeing method and properties of polymaleic acid dyes on cotton

A polymaleic acid dye based on poly(maleic anhydride) was synthesised and evaluated in the dyeing of cotton. A series of dyeing auxiliaries were examined, and results showed that a composite auxiliary agent consisting of 20 g/l of zinc nitrate and 30 g/l of dicyandiamide was the most effective when a conventional pad‐dry‐cure dyeing process was used. The fixation could reach 99% and the wash and dry rub fastness could reach grade 4 and grade 4–5 respectively. The decrease in tearing strength of the dyed cotton was between 17.8 and 32.1%.     

Dyeing of poly(lactic acid) fibres with synthesised novel heterocyclic disazo disperse dyes

Poly(lactic acid) (PLA) is the first melt‐processable, renewable, sustainable and biodegradable natural‐based synthetic fibre. It has a broad range of uses and combines ecological advantages with outstanding performance in textiles. PLA fibre, as an aliphatic polyester, can be dyed with disperse dyes. Apart from the limited number of commercial disperse dyes, disperse dye exhaustion on PLA is generally lower than that on  poly(ethylene terephthalate) (PET). In this study, new heterocyclic disazo disperse dyes, substituted with methyl, nitro and chloro groups at their ortho‐, meta‐ and para‐ positions, synthesised in our previous study, were applied to PLA and PET fibres to examine their dyeing performance, and colour fastness and dye exhaustion properties. Different shades of yellow, orange, reddish brown and brown were obtained. Most of the synthesised novel heterocyclic disazo disperse dyes exhibited good build‐up properties with high K/S levels on both fibres. Para‐ bonding substituent provided higher K/S values than meta‐ and ortho‐ positions for –NO₂ and –Cl substituents for both fibres. Overall, the most synthesised novel heterocyclic disazo disperse dyes in this study exhibited good build‐up properties with high K/S, exhaustion and wet fastness levels on both PLA and PET fibres.      

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.     

Dyeing of cationised cotton with acid dyes

The production of cationised cotton fabrics, via Sandene 8425, 1, 1-dimethyl-3-hydroxy azetidinium chloride and 1, 1-diethyl-3-hydroxy azetidinium chloride, greatly enhances the exhaustion and fixation of acid dyes. This paper shows that these dyes can be used in the absence of salt in a neutral medium. Wash fastness, light fastness and other properties were studied.     

Dyeing properties of PECH‐amine cationized cotton with acid dyes

The dyeing properties of cationic cotton dyed with acid dyes are examined in this study. For comparison, nylon 6 and untreated cotton are dyed by the same acid dyes (Sandolan Red MF‐2BL, Sandolan Golden Yellow MF‐GL, and Sandolan Blue MF‐GL). A cationic agent, polyepichlorohydrin‐dimethylamine (PECH‐amine), is used to modify cotton fabric. Significant increase in color yield is observed for cationic cotton over untreated cotton because of the introduced positively charged sites by cationic modification. Deeper shades are obtained in all cases with cationic cotton. All of the acid dyes used in this study show significant hooking behavior with both cationic cotton and nylon. © 2006 Wiley Periodicals, Inc. J Appl Polym Polym Sci 100: 3302–3306, 2006     

Dyeing properties of wool treated with liquid ammonia

Wool fibre and fabric have been treated with liquid ammonia and their surface characteristics investigated by means of SEM and ESCA techniques. The treated specimens were dyed with levelling and milling acid dyes. Although no changes in nitrogen content and fibre surface properties were detected, their dyeing rate was increased considerably as was saturation dye exhaustion. Dyeing properties were similar to those of wool treated with low-temperature plasmas by glow discharge. Fabrics treated with liquid ammonia were dyed at various temperatures in the range 30–80°C, and dye uptake was similarly increased.     

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     

Latest developments in the low-temperature dyeing of wool with 1:2 metal-complex and milling acid dyes*

The advantages of dyeing wool at low temperatures with metal-complex and milling acid dyes are examined. Details of variations in conventional dyeing practice are discussed in detail and recommendations for applying selected dyes are given. The cost implications of dyeing at temperatures below the boil are reviewed, and some techniques for the low-temperature dyeing of woo/nylon blends briefly mentioned.     

Synthesis of polycondensable anthraquinone dyes and coloured nylon fibres: II

Without addition of any metal ions or other catalysts, 1-chloroanthraquinone reacts readily with 6-aminocaproic acid or hexamethylenediamine in dimethylsulphone as solvent to give 1-(6-aminocaproic acid)anthraquinone and 1-(6-aminohexyl)amino]anthraquinone, respectively. 1,5-Dichloro-or 1,8-dichloroanthraquinone can also be used in this reaction to give bis-substituted derivatives of anthraquinone. As a kind of functional dye, which contains −COOH or −NH₂ groups and dissolves easily in nylon melt, the products were designed for preparing coloured nylon by polycondensation with caprolactam or nylon-6,6 salt. Nylon fibres with different colours were obtained directly. ©1997 SCI     

Synthesis of polycondensable anthraquinone dyes and coloured nylon fibres: I

The reaction of dihydroxyanthraquinone (DHA) and amines in the presence of catalyst has been reported. We found that DHA reacted easily with hexamethylenediamine in chloroform or toluene without addition of any catalyst, and mono-or dihexamethylenediamine-substituted anthraquinone, a violet green colourant, was formed. Using the colourant as a comonomer in the polycondensation of caprolactam or nylon-6,6 salt, coloured nylon-6 and nylon-6,6 fibres were prepared.     

Synthesis of polycondensable anthraquinone dyes and coloured nylon fibres: III

A series of 1,5-diaryl- and 1,8-diaryl-substituted anthraquinone dyes, which contain −COOH or −NH₂ groups, were prepared. The aryl-substituted anthraquinone dyes possess excellent thermostability and will keep their original colour in polycondensation with caprolactam at 260–280°C. With different aryl substituents the anthraquinone dyes exhibit different colours and can be used to prepare a series of coloured nylon-6 fibres. ©1997 SCI     

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.     

Dyeing of nylon with reactive dyes. Part 1. The effect of changes in dye structure on the dyeing of nylon with reactive dyes

The dyeing behaviour of seven red commercial cellulosic reactive dyes, all based on the same chromophore and possessing one or more reactive group, and one to three chromophore units, were evaluated on nylon. Fixation levels appeared to be independent of the number of either reactive groups or chromophore units. Also, the degree of sulphonation, per se, appeared to have little effect on fixation, whereas the type of reactive group was important. The major determinant of dye fixation appeared to be associated with the shape of the molecule and the type, not the number, of reactive groups.