The Oxidation of Cotton Cellulose in the Presence of Direct Cotton Dyes

Datye, Keshav V.; Nabar, G. M.; Shroff, G.G.

doi:10.1177/004051756103100909

Cited by 8 publications

(4 citation statements)

References 18 publications

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“…They concluded that fading is normally an oxidation of dye on a nonprotein but a reduction on protein, and that probably nonprotein substrates do not take part in the initial fading reaction. This was later confirmed by Datye et al [7], but the protein substrates do take part, and their work identified the specific side chain responsible for reduction as histadine (perhaps also tryptophane). Ahmed and Mallet [ 1 ], working along similar lines, observed that the mechanism of fading of azo dyes on polypropylene in the absence of air differed from that normally observed on a nonprotein substrate, i.e., there were indications of a reductive mechanism.…”

mentioning

confidence: 74%

“…The problem of the effects of tension on the properties of mercerized cotton fibers has been the subject of many research reports [5,6,7,9]. Researchers generally concede that slack mercerization of cotton followed by restretching in the mercerization alkaG to about its original length results in a substrate that loses less strength on treatment with crosslinking reagents than does nonpretreated cotton.…”

Section: Characteristic Fading Curvesmentioning

confidence: 99%

“…Murphy et al [6,7] mercerized and stretched cotton yarns and found that the fabric made from such yarn loses less strength than that made from untreated yams or that made from slack mercerized yarns after durable press treatment. They report that if 2-ply mercerized yarn was used, with the twist in the ply equal and opposite to the twist in the singles yarn, almost no strength loss occurred during resin finishing of yam or fabric.…”

Section: Characteristic Fading Curvesmentioning

confidence: 99%

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Mechanism of Light Fading of Azo Dyes on Polyvinyl Chloride and Poly(ethylene Terephthalate)

Shah

Jain

1984

Textile Research Journal

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A series of monoazo compounds based on phenyl azo-β-naphthol and phenyl azo-8-hydroxyquinoline were applied to polyvinyl chloride and poly(ethylene terephthalate), respectively. From the relation between the electron attracting or withdrawing properties of the substituents in the benzene nucleus and relative fading rates, the conclusion was that the fading reaction in both the dye-fiber systems is probably oxidative. This conclusion agrees with that from an earlier analysis of fading products of anthraquinone disperse dyes on polyester. It is therefore clear that both polyvinyl chloride and poly(ethylene terephthalate) conform with the general observation that fading on any nonprotein is oxidative, provided the oxygen has access to the dye.Lightfastness of phenyl azo-β-naphthol dyes on polyvinyl chloride and that of phenyl azo-8-hydroxyquinoline dyes on poly(ethylene terephthalate) was very low. Also, in both the systems, the dyes in the substrate were in the form of a collection of particles of many different sizes.The fading of dyed materials by light has long been a subject of investigation, yet surprisingly little is known of the fundamental photochemical reactions involved [ 10,12,13], mainly because of the complex nature of dye-fiber systems. The reactions are not necessarily the same as those of dyes in solution [9], which are probably simpler and have been more widely studied [9,10,12,19]. Calvert and Pitts [4] have stated that &dquo;In general ... solid-phase photochemistry has not received the amount of quantitative effort afforded the liquid and gaseous systems,&dquo; and they have suggested that one reason for this neglect lies in the difficulty of dealing with the very high light absorption of many solids.This difficulty can be overcome if dyes are adsorbed in transparent films of solid polymers and changes caused by irradiation readily measured spectrophotometrically. Even then, however, many complicating factors are present, e.g., the physical state of the adsorbed dye, that is, the size and location of its associated particles, structure of the dye, extent of penetration of the dye, diffusion of air, moisture, gases, etc. Because of these and many other factors, the lightfastness of a dye differs when applied to different textile substrates.A dye may show very good lightfastness on one fiber and poor on another one. For example, the same anthraquinone dyes show moderate to good lightfastness on nylon and cellulose acetate but poor on polyester [ 13]. A number of studies have attempted to account for such variations in lightfastness. One line of work has ascertained the nature of chemical reactions taking place during fading of dyes, mainly to show oxidation and reduction, and another has reported on the physical state of dyes in fibers. Kienle et al. [ 16] were probably the first to study quantitatively the fading rates of a series of benzene azo-R-acid dyes on wool and gelatin. They found that electron attracting groups (e.g., -N02) accelerate fading and electron repelling ones (e.g., ...

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mentioning

confidence: 74%

Section: Characteristic Fading Curvesmentioning

confidence: 99%

Section: Characteristic Fading Curvesmentioning

confidence: 99%

See 1 more Smart Citation

Mechanism of Light Fading of Azo Dyes on Polyvinyl Chloride and Poly(ethylene Terephthalate)

Shah

Jain

1984

Textile Research Journal

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“…Indeed, many dyes actually protect fibres against photolytic degradation, which is an opposite effect to that expected on this hypothesis (e.g. 30). Moreover, there is direct evidence that anionic dyes linked by a covalent bond to anodic alumina films fade much more rapidly than similar dyes not so linked (29).…”

Section: I ' U S I O Nmentioning

confidence: 99%

Quantum Efficiency Measurements of Fading of some Disperse Dyes in Nylon and Polyester Films and in Solution

Giles

Hojiwala

Shah

1972

Journal of the Society of Dyers and Colourists

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Several anthaquinone and azo disperse dyes adsorbed on films of polyester and nylon 6. 6 and dissolved in a mixture of acetone and water have been faded by various lines in the visible spectrum, and the quantum yields (φ) determined by means of the Parker‐Hatchard potassium ferrioxalate actinometer. φ for adsorbed dye lies between ca 10‐4 and 10‐6, decreasing with increase in exposure time, probably owing to the presence of associated dye, and with increase in wavelength of illumination. Values for dye in solution are 20–60 times as high as those for adsorbed dye. The low values for adsorbed dye are the result of a combination of several factors, including association of dye, retardation of gaseous diffusion by the substrate, and the shield or cage effect of the surrounding polymer substrate.

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Mechanism of light fading of dyes on cellophane and poly(ethylene terephthalate)

Shah¹,

Srinivasan²

1977

J. Biochem. Toxicol.

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Studies of relative rates of fading of dyes and Hammett 5-value of substituents in their molecules lead to further evidence that fading of azo dyes on Cellophane and poly-(ethylene terephthalate) is probably an oxidation type of reaction. Absorption spectra of the same dye on these two substrates tend to indicate a very high state of aggregation of dyes on Cellophane as compared to that on poly(ethy1ene terephthalate).

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The Oxidation of Cotton Cellulose in the Presence of Direct Cotton Dyes

Cited by 8 publications

References 18 publications

Mechanism of Light Fading of Azo Dyes on Polyvinyl Chloride and Poly(ethylene Terephthalate)

Mechanism of Light Fading of Azo Dyes on Polyvinyl Chloride and Poly(ethylene Terephthalate)

Quantum Efficiency Measurements of Fading of some Disperse Dyes in Nylon and Polyester Films and in Solution

Mechanism of light fading of dyes on cellophane and poly(ethylene terephthalate)

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