Fading characteristics of a disperse dye on cellulose triacetate, polyester and nylon under monochromatic light radiation

Light fastness of CI Disperse Blue 165 dye on cellulose triacetate, polyester and nylon fabric substrates exposed to monochromatic light was examined on a radiant energy basis. The action spectra indicated a strong effect on the substrate-fading characteristics: nylon exhibited poorer light fastness in the visible and ultraviolet light range than polyester and cellulose triacetate. Two specific fading peaks were found for the nylon substrate, which were different to those found for the polyester and cellulose substrates. It was shown that polyester exhibited the best light fastness properties overall. The colour changes in the fading process suggested that the fading products of the dye on nylon (where reduction occurred) were different from those on the polyester and cellulose triacetate substrates (where oxidation occurred).     

Investigation into the effect of a plant‐derived stabiliser on the light and wash fastness of sulphur‐dyed cotton and nylon fabrics

In this study, cotton fabric and nylon fabric were dyed with a range of commercial sulphur dyes and the light and wash fastness of the coloured fabrics was investigated. The effect of after‐treating the coloured cotton and nylon fabrics with a tannin‐based commercial product, Bayprotect Cl, in the presence or absence of sodium sulphate in the treatment bath, was found to significantly improve the light fastness of the sulphur‐dyed cotton, and the photoprotective effect was partially stable to ISO 105‐C06 washing. In addition, the tannin‐based after‐treatment also improved the colour stability of the dyed fabrics to the perborate‐based ISO 105‐C06 washing. The possible mechanisms for the improved fastness properties are also discussed. The application of sulphur dyes to nylon is potentially commercially useful but has been limited because of the reported poor light fastness of the dyeings. The photoprotective effect of the tannin‐based after‐treatment was investigated with a view to providing the necessary commercial performance. However, it was established that on this fibre, the light fastness improvement was marginal, and the associated wash fastness to oxidative bleach‐based ISO 105‐C06 washing was limited.     

Coloration of cellulose nanofibres with pigments

Electrospun nanofibrous mats are popular for their wide technological applications as medical, filtration, sensing and high performance textiles. The potential for coloration of electrospun nanofibrous mats for aesthetic purposes has also been explored recently, and the pigment coloration of cellulose electrospun nanofibrous mats is reported for the first time in this paper. Cellulose acetate electrospun nanofibrous mats were fabricated using electrospinning followed by treatment with sodium hydroxide to synthesise regenerated cellulose electrospun nanofibrous mats. Then the cellulose mats were coloured with commercially available pigments by a pad‐dry‐bake method. Excellent K/S and colour fastness to both washing and light were produced with the application of three commercial pigments. The pH and total dissolved solids content of the coloration wastewater, as well as the mechanical properties of the electrospun nanofibrous mats, were also tested. Attenuated total reflection‐Fourier Transform infrared spectroscopy and scanning electron microscopy analysis were used for characterisation.     

The Anomalous Fading of Some Fluorescent Dyes and Brighteners on Hydrophilic Fibres

The fastness to light of a number of fluorescent yellow dyes and fluorescent brightening agents (FBA) on several fibres at different concentrations has been assessed both visually and by colour-difference measurements. One acid dye on wool, six FBA on wool and two FBA on cotton showed anomalous fading (i.e. the light fastness decreased with increasing concentration). Results of extraction experiments showed that this could be accounted for by the formation of coloured decomposition products from the dye or FBA and, with wool, from the fibre also. With FBA on wool and cotton there appears to be an optimum concentration above which both the fastness to light and the whiteness fall.     

The graft printing of silk fabric in the presence of sulphamic acid

The effect of printing silk fabrics in the presence sulphamic acid has been investigated. Sulphamic acid introduces sulphonate groups into silk's structure and confers good resist properties for acid dyes on silk. An increased uptake of basic dyes has also been found. The light fastness of such dyeings was better than on ungrafted silk, being similar to values obtained on acrylic substrates. White and coloured resist effects have been investigated.     

Role of quaternary ammonium salts in improving the fastness properties of anionic dyes on cellulose fibres

The object of this study was to review the developments taking place during 1990–2005 regarding the use of quaternary ammonium salts as dye fixing agents for improving the fastness properties of anionic dyes on cellulose fibres. As far as fastness properties are concerned, this review is restricted only to fastness to light, washing and water treatments.     

Substituent Effects on the Colour,Dyeing and Fastness Properties of Trisubstituted 4–N–β–Hydroxyethyl–N–β–Cyanoethylaminoazobenzenes

School of Chemistry and Chemical Technology University of Bradford Bradford West Yorkshire BD7 1DP The synthesis of a series of 2′, 4′, 6′-trisubstituted derivatives of 4–N–β–hydroxyethyl–4– N–β–cyanoeth ylaminoazobenzene is reported, and the effect of the nature of the substituents on the colour, dyeing and fastness properties of these dyes is described. The dyes coloured synthetic–polymer fibres well, with the exception of those containing a methylsulphonyl group, which gave weaker dyeings on polyester. Dyes substituted by 2′-nitro groups tended to have poor light fastness, and reasons for the variations in the light fastness of monoazo dyes of this type are discussed.     

Digital ink-jet printing of regenerated cellulose nanofibrous mats with reactive inks

The versatility of nanofibres enables them to be used for various technological applications such as filtration, biomedicine and healthcare, composites, protective and functional textiles. Recently, in addition to the functional properties of electrospun nanofibrous mats, their aesthetic properties have been explored. Herein, attempts have been made to develop digital ink-jet printing of regenerated cellulose nanofibrous mats with reactive inks. First, a cellulose acetate polymer was created to fabricate electrospun cellulose acetate nanofibrous mats, which were then converted into regenerated cellulose nanofibrous mats through deacetylation. Next, the cellulose nanofibrous mats were treated with an alkaline solution then coloured with four (cyan, magenta, yellow and black) commercially available reactive inks by a digital ink-jet printing method using a piezoelectric digital ink-jet printer. Various parameters were investigated, including the optimal concentration of the pretreatment agents, fixation temperature and time, colour yield and the absorbency of the electrospun nanofibrous mats. The digital ink-jet printed cellulose nanofibrous mats exhibited excellent colour yield and colour fastness properties. Morphological analysis through scanning electron microscopy and chemical analysis through Fourier Transform–infrared were also carried out.     

New Dyes and their Intermediates for Synthetic-polymer Fibres

Halogenobenzothiazolylazo dyes were prepared by coupling diazotised halogeno-2-aminobenzothiazoles to N-β-hydroxyethyl-N-β-cyanoethyl-m-toluidine. The colour and fastness properties of the dyes on secondary cellulose acetate and on polyester fibre are compared with respect to the position and the nature of the halogen atom. Dyes containing 4-halogeno atoms have the highest fastness to sublimation on polyester fibres; the fastness to light of the dyes is considerably higher on secondary cellulose acetate than on polyester fibres, but differences between individual dyes are small.     

Dielectric loss microwave degradation of polymers: Cellulose

The pyrolysis of organic waste polymers to produce fuels and chemicals is of interest to augment petroleum-based processes. The wide variety of pyrolysis products of low yield and the uncertain role that heat transfer rate plays in determining these have been deterrents to utilization in the past. A possible approach to increased selectivity for products is to heat them rapidly and homogeneously with the aim of narrowing the product distribution. A very rapid means of homogeneous heat transfer throughout the substrate is microwave heating. A laboratory study has been done to determine what effect high-intensity microwave energy has on the thermal degradative pathways of cellulose. The product distribution found when cellulose is pyrolyzed in the absence of a microwave discharge is similar to that found in conventional furnace pyrolysis. The major products are levoglucosan (27%), carbon dioxide (2–5%), water, and charred residue. However, the total heat-up and reaction times for even large pellets are reduced to less than 2–3 min when high-intensity microwave irradiation is employed. Effects of pressure and microwave power are reported. Low external gas temperature also prevents secondary reactions.     

The use of triarylmethane dyes on aluminium

Coatings have been formed on the surface of unanodised aluminium electrolytically treated in an aqueous solution of tin sulphate and a triarylmethane dye. The coatings produced had a good decorative appearance, good adhesion and were 3–5μm thick. The coloured films had excellent light fastness but poor resistance to corrosion resistance. The dyes showing the most promise for this application were CI Acid Blue 9 and CI Acid Green 5. These dyes interfered in the current flow, in so doing modifying the surface topography and the semiconductive properties of the superficial aluminium oxide film formed during the colouring treatment. The dye fragmentation, cyclisation and dimerisation products derived during the electrolytic treatment resulted in the formation of organotin compounds.     

Synthesis and salt‐free dyeing characteristics of cationic reactive dyes containing polyetheramine segments

A series of cationic reactive dyes containing both quaternary ammonium and polyetheramine as soluble groups and monochlorotriazine as a reactive group have been synthesised and applied to cellulose fibre by salt‐free exhaust dyeing. Investigation of the synthesis method and dyeing properties of these cationic reactive dyes showed that the best pH value for these dyes is 6, and also that these cationic reactive dyes give a high substantivity to cellulose. In the salt‐free dyeing process, their adsorption was consistent with the Langmuir isotherm during the primary exhaustion stage, but in the secondary exhaustion stage the adsorption was in accordance with the Freundlich isotherm, and their secondary exhaustion reached up to 96% and above. Moreover, the degree of fixation, the levelling, and the transfer properties on cotton fabric were good. Light fastness reached grade 5–6, washing, perspiration, and dry rubbing fastness reached grade 4 and above, but wet rubbing fastness reached only grade 3–4.     

Pad dyeing of cellulose acetate nanofibres with disperse dyes

In addition to a number of applications of nanofibres in technical fields such as medical, filtration and biosensing, nanofibres are recently being widely explored in terms of apparel use. Past work has focused on the functional properties of nanofibres for apparel use. Coloured nanofibres were produced to investigate their aesthetic properties for the potential application to apparel. Webs of cellulose acetate nanofibre were electrospun and dyed with a high energy level CI Disperse Red 167:1 dye and a low energy level CI Disperse Blue 56 dye using the continuous pad–dry–bake method. Results revealed that the high energy level dye produced better colour yield than the lower energy level dye. The dyed cellulose acetate nanofibres produced acceptable colorimetric values, colour yield and colour fastness. Young’s modulus of dyed nanofibres increased by threefold in comparison to the undyed cellulose acetate nanofibres. Scanning electron microscopy images showed good morphology with the smooth surface of the dyed cellulose acetate nanofibres.     

Dyeing Properties of Monoazo Dyes Derived from 5-Nitro-2-aminobenzothiazole-3N-oxide on Various Synthetic-polymer Fibres

The preparation of new monoazo dyes from substituted 5-nitw-2-aminobenzothiazole-3N-oxides and aniline coupling components and their dyeing properties on polyester, cellulose acetate, nylon 6 and acrylic fibres are reported. The dyes exhaust well on synthetic-polymer fibres to give bright dyeings of good fastness to dry cleaning and sublimation. Their light fastness is better than that of dyeings of the unnitrated dyes. However the transferability of the nitro dyes is such that they are unsuitable for sublimation printing. The transferability of other dyes derived from 2-aminobenzothiazole-3N-oxide and its derivatives is also assessed.     

An approach to sustainable coloration of lyocell fabrics by screen printing using extracts of leaves and bark from eucalyptus

This paper presents an initial study from a more extensive programme of research at the design/technology interface that is focused on the use of design methodology as a means to lower the environmental impact of fashion clothing. The leaves and bark that are byproducts of the responsibly farmed eucalyptus used in the manufacture of lyocell fibres were extracted with water to provide a source of natural colour. Lyocell fabric, which required minimal preparation, was screen printed with an aqueous paste containing only the extracted colour and a natural thickener to provide attractive golden‐yellow prints. The printed fabrics demonstrated surprisingly good fastness towards light, washing and rubbing. A mordanting pretreatment of the lyocell with alum modified the colour of the naturally coloured prints to become stronger and duller, but provided no advantage in terms of technical performance. The outcome presents a potentially useful model for the development of sustainably coloured fashion textile products.     

Dyeing Properties of Monoazo Disperse Dyes Containing 5- and 6-Aminoindazoles as Diazo Components

In this study the effects of various coupling components, used in conjunction with 5- and 6-aminoindazoles as diazo components, on the spectral characteristics and dyeing properties of dyes for cellulose secondary acetate (acetate), nylon 6 and polyester have been investigated. Eight new disperse dyes suitable for acetate, nylon 6 and polyester were synthesised. In general, when disperse dyes are applied in the dyeing of nylon 6 the colour fastness to water is very low. However, we found that the new dyes synthesised showed good dyeing properties in all cases, on all three fibre types. Some of the dyes obtained using 5- and 6-aminoindazoles gave bright dyeings of good fastness to light, washing, perspiration, dry cleaning and rubbing. Some bright dyeings on polyester were also obtained.     

Economical and Efficient Fading Lamps*

Tests have been made with over 300 dyed or pigmented materials exposed to mercury-tungsten or mercury lamps. The colorations were of a wide range of hue and light-fastness properties (1 to 8 and above) and in several depths on different substrates. The mercury-tungsten fluorescent lamp (500 W) gave results identical with those obtained with daylight or xenon arclight for 75% of the very varied selection of 174 patterns examined, and 25 % were within one-half of a grade, except for five which differed by one grade. When the blue standards are faded in this lamp (at 45% r.h.), they have an average interval factor of about 2.1. The required times of exposure are similar to those for the xenon arclight. The equipment required is extremely simple, and its initial and operating costs are considerably lower than those of methods hitherto used for testing in artificial light. The equipment can readily be used on the laboratory bench and is suitable for routine testing of the light fastness of any coloured material. In addition to the control of humidity, temperature control is possible, though this is not usually necessary. The mercury-vapour lamp (400 W) has also been similarly examined, using 138 patterns. It is not recommended for general use but is valuable for routine sorting tests of materials of very high fastness (BS grading above 7). The blue standard patterns fade, under exposure to these lamps, in the same sequence and with similar interval spacings, as in daylight or xenon light.     

合成纤维及其混纺纤维用染料的研究 Ⅰ.用于锦纶染色的含β-羟乙基砜硫酸酯基活性分散染料

本文综合了应用于锦纶染色的弱酸性染料酸性浴上色的高竭染率,活性染料与纤维的共价键结合,分散染料在纤维上迁移、匀染、盖染性好等优点,提出一类含β-羟乙基砜硫酸酯基的活性分散染料。用分子较小的分散染料结构,以含β-羟乙基砜硫酸酯为活性基;在弱酸性浴中染色,再在弱碱性浴中与聚酰胺纤维反应成共价键结合。 合成了一系列偶氮型和蒽醌型染料。进行了合成工艺、对锦纶的染色性能以及染色锦纶的牢度等试验。并讨论了染料与聚酰胺纤维的结合 这类染料可用于锦纶66和锦纶6丝纺、弹力锦纶丝和针织品,还可用于桑丝、柞丝及其与人造丝的提花织物。这类染料在锦纶上色泽鲜艳,竭染率较高,益染性优良,耐晒、耐湿处理等牢度较好,适于各种锦纶织物的染色。这类活性分散染料,具有酸性染料、活性染料和分散染料染锦纶的主要特点。     

Light-induced colour changes in dyes and materials

The present knowledge of the properties and reactions of photoexcited states of dyes and materials is presented and discussed. It is shown that the most probable result of the absorption of daylight by the majority of coloured products in practical use is the decomposition of the colourless substrate or additives, or their photooxidation. In both reactions, radicals are produced which can convert dyes or coloured pigments into compounds that are colourless or possess a different colour. The conclusions drawn may be useful in the interpretation of anomalous light stabilities of coloured products, and help develop products with improved lightfastness.