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  • 1
    Electronic Resource
    Electronic Resource
    Electrokinetic studies of cellulosic fibres (1978)
    Springer
    Colloid & polymer science 256 (1978), S. 1021-1026 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Summary Results on changes in s. c. d. of the cotton fibres dyed with reactive dyes have been reported. In general, the s. c. d. decreased as a result of the reaction between dye and fibre, the decrease being proportional to the concentration of the dye in the fibre. These results have been explained on the basis of the reduction in the effective surface area of the fibre responsible for the electrokinetic phenomena as a result of the reaction between fibre reactive dye. Results on correlation between the s. c. d. and the zeta potential revealed that there is a linear correlation between the two parameters in case of all the dyes studied. For a bifunctional reactive dye, however, a separate linear plot was obtained. On extrapolation the linear plot representing the bifunctional dye passed through the origin, while the extrapolated linear plot for the monofunctional dye gave a positive intercept on the zeta potential axis, which was attributed to those free -OH groups in the fibre substance which contributed to the negative value of zeta potential but, at the same time, were “blocked” in such a way that they are ineffective in contributing to the s. c. d. In case of the bifunctional reactive dye, on the other hand, such -OH groups on the cellulose chain are brought nearer to each other due to the formation of crosslinks between two cellulosic chains, thus inducing H-bond formation between them, in addition to the bridge formation through the bifunctional dye molecule. These results have been confirmed by comparing surface area available for nitrogen adsorption in case of fibres containing equivalent quantities of the monofunctional and the bifunctional reactive dyes. Experimental technique employed in these investigations permitted the use of the originalHelmholtz-Smoluchowskii equation without the application of Bikerman's correction factor due to swelling of fibres in the plug.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01520990
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  • 2
    Electronic Resource
    Electronic Resource
    Grafting onto polyester fibres (1984)
    Springer
    Colloid & polymer science 262 (1984), S. 127-130 
    Details
    ISSN: 1435-1536
    Keywords: Zeta potential ; graft-copolymerisation reactions ; acrylamide-acrylic acid graft mixtures ; amphoteric polyester fibres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The influence of graft-copolymerisation reaction between polyester fibres and mixtures of acrylamide (AAm) and acrylic acid (AA) monomers on zeta potential (ζ) of the grafted polymer has been studied. The polyester fibre was rendered amphoteric in nature due to the introduction of the AAm-AA graft mixtures in the substrate. The (−ζ) increased to a considerable extent at higher pH values of the streaming solution due to increased dissociation of -COOH groups of the AA graft component present in the mixture. With the decrease in pH on the acidic side, decrease in (−ζ) was brought about due to suppression of the dissociation of -COOH groups and increase in the protonation of -CONH2 groups. It was observed that (−δζ/ΔpH) ratio serves as a measure of the amphoteric character of the polymer containing mixtures of AAm-AA graft.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01417545
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  • 3
    Electronic Resource
    Electronic Resource
    Electrokinetic studies of cellulosic fibres (1982)
    Springer
    Colloid & polymer science 260 (1982), S. 811-814 
    Details
    ISSN: 1435-1536
    Keywords: surface conductivity ; reactive dyes ; cellulose ; cross-links
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Results on surface conductivity of cotton fibres dyed with reactive dyes have been reported. In general the surface conductivity values were higher in alkaline pH, but lower in acidic pH as compared to the neutral pH. This observation has been attributed to the contribution of the functional groups present on the dye molecule reacted with the fibre. Results on the surface conductivity of fibres dyed with mono- and bifunctional reactive dyes suggest that dyes react with the hydroxyl groups of the fibre, and that the bifunctional dye molecule forms a crosslink between two cellulosic chains.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01452075
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  • 4
    Electronic Resource
    Electronic Resource
    Electrokinetic studies of cellulosic fibres I. Zeta potential of fibres dyed with reactive dyes (1976)
    Springer
    Colloid & polymer science 254 (1976), S. 1030-1041 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Der Einfluß der Reaktion zwischen einem reaktiven Farbstoffmolekül und Baumwollzellulose auf dasζ-Potential der Zellulosefasern wurde mit der Strömungspotential-Methode untersucht. Als Ergebnis einer solchen Reaktion sank der negativeζ-Potentialwert ab, und die Abnahme war proportional dem Betrag an Farbstoff, der in Reaktion trat. Im Hinblick auf den Einfluß verschiedener struktureller Eigenschaften eines reaktiven Farbstoffmoleküls auf dasζ-Potential der gefärbten Faser wurde festgestellt, daß letzteres unabhängig vom Typ des Reaktions-systems war, abet sehr abhängig von der Zahl der −SO3H-Gruppen im Farbstoffmolekül und der Konstitution des chromophoren Systems. Ein zweifunktionaler reaktiver Farbstoff (Remazol Black B — C. I. Reactive Black 5) bildet Vernetzungen zwischen Zelluloseketten und erniedrigt beträchtlich das negativeζ-Potential der gefärbten Fasern, verglichen mit einem Farbstoff in modifizierter Form, so daß er als monofunktioneller Farbstoff wirkt. Dieset zweifunktionale Farbstoff induziert auch Wasserstoffbrücken in der Nachbarschaft der Vernetzungsstellen. Farbstoffe von Trichlorpyrimidin-Typ sind weder streng monofunktionell noch voll bifunktionell. Sie liegen in der Mitte.
    Notes: Summary The influence of reaction between a reactive dye molecule and cotton cellulose on the zeta potential of the cellulosic fibres has been studied by streaming potential method. As a result of such a reaction the negative value of zeta potential was decreased and the extent of this decrease was proportional to the amount of dye entered into the reaction. With respect to the influence of various structural features of a reactive dye molecule on the zeta potential of dyed fibres, it was observed that the zeta potential was independent of the type of reactive system but was very much dependent on the number of −SO3H groups in the dye molecule and the chemical constitution of the chromophoric system in the dye structure. A bifunctional reactive dye (Remazol Black B —C. I. Reactive Black 5) has been shown to form crosslinks between cellulose chains and bring about considerable lowering of negative zeta potential of the dyed fibres as compared to the equivalent amount of same dye but in the modified form to act as a monofunctional reactive dye. This bifunctional dye was also observed to induce H-bonding in the vicinity of the sites of cross-links. Trichloropyrimidine type of dyes have been found to be neither completely monofunctional nor fully bifunctional but seem to lie in between the monofunctional and bifunctional types of dyes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01516922
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  • 5
    Electronic Resource
    Electronic Resource
    Grafting on polyester fibers (1975)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 19 (1975), S. 461-480 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Acrylic acid (AA) and acrylonitrile (AN) were used to carry out grafting on polyester (PE) fibers using the techniques of initiation by γ-radiation as well as benzoyl peroxide. The nature of the grafted fiber substance was found to be the same, irrespective of the grafting technique. Extent of grafting depended upon the time, concentration of the initiator, and the monomer as well as on the irradiation dose. The increase in the moisture regain was directly proportional to the amount of graft in the fiber. AA grafted fibers were rendered more hydrophilic than AN grafted fibers for equivalent amount of grafts. Considerable improvement in dyeability of the PE fibers was possible through grafting. About 50% to 100% improvement with disperse dyes was observed in case of PE fibers containing 22.4% and 9.0% graft of AA and AN, respectively. Intense fast dyeing with direct and basic (cationic) dyes was also possible, and the dye content was proportional to the extent of graft introduced in the fiber. The CN groups were reduced to NH2 groups in the AN graft on the fiber. In this way, deep, fast, and bright dyeing was obtained with reactive dyes. Electrokinetic studies were carried out on the grafted fibers. With the increased amount of AA graft, the maxima in the zeta potential curve shifted toward higher acidic pH as greater amounts of alkali was utilized by the —COOH groups in the graft. In this respect, CN groups were less sensitive due to their lesser polarity as compared to the carboxylic groups. It was observed from surface charge density (S.C.D.) studies that the effective surface area of the fiber decreased with the increase in the amount of graft, particularly in case of AN graft. Surface conductivity (S.C.) studies revealed that with increase in the number of polar groups (—COOH) on the surface of the fiber, the S.C. increased with the increase in the amount of AA graft. In case of AN grafts, the reduction in effective surface area of the fiber played a more important role than the contribution by the CN groups to surface conductivity.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1975.070190212
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  • 6
    Electronic Resource
    Electronic Resource
    Grafting onto polyester fibers. II. Kinetics of grafting of acrylic acid, acrylonitrile, and vinyl acetate onto polyester fibers (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 2133-2138 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The kinetics of grafting of acrylonitrile, acrylic acid, and vinyl acetate onto polyester fiber by catalytic initiation and radiation were studied. The energy of activation determined for acrylic acid grafting by the catalytic method was 10.7 kcal/mole and that for vinyl acetate grafting by the radiation method, 11.7 kcal/mole. In the case of acrylonitrile grafting by the catalytic method, the rate of grafting decreased with increase in temperature of grafting, showing the differential behavior of the precipitating type of polymer from that of homogeneous polymerization.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070230723
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  • 7
    Electronic Resource
    Electronic Resource
    Kinetics of hydrolysis, acetylation, and deamination reactions on polyamide fibers in homogeneous medium (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 275-294 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Chemical reactions on polymers in homogeneous medium were used to characterize the structure of the macromolecules. The polymer was in the form of polyamide fibers dissolved in m-cresol to give a fairly highly concentrated solution (approximately 6%). Kinetic studies of hydrolysis, acetylation, and deamination reactions on the polyamide fibers were carried out in homogeneous medium at different temperatures. All the three reactions studied followed first-order kinetics. Rate constants and apparent activation energies were determined for these reactions, which show two rates - an initial fast rate followed by a slow one. A new microfibrillar model of the polymer dissolved in m-cresol is proposed, and the existence of two rates is explained on the basis of the two-phase structure of the proposed microfibril. The fast rate is attributed to the free chain segments, and the slow rate is shown to correspond to the regions which are strongly hydrogen bonded and which hold the various chains together to give the microfibrillar structure of the polymer in the homogeneous phase. The apparent activation energy for hydrolysis was 3.20 and 0.18 kcal/mole for the fast and slow rates, respectively. The apparent activation energy values for acetylation were 1.50 and 0.80 kcal/mole, while those for the apparent deamination reaction were 6.90 and 4.60 kcal/mole, respectively. Lower values of apparent activation energies are attributed to the ease of reaction in the difficult-to-penetrate regions of the microfibril due to the role played by the solvent of the homogeneous phase in carrying the reacting species inside these regions while simultaneously breaking the hydrogen bonds between the polypeptide chains. The apparent deamination reaction is shown to be a resultant reaction of simultaneous deamination and “amination” through hydrolytic breakdown of the polypeptide chain.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070230125
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  • 8
    Electronic Resource
    Electronic Resource
    Electrokinetic properties of acrylic acid- and methacrylic acid-grafted polypropylene during chemically initiated graft copolymerization (1984)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 2989-2996 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Electrokinetic properties such as zeta potential (ζ), surface charge density (σ) and surface conductivity (Ks) of polypropylene fibers and those grafted with acrylic acid and methacrylic acid have been studied using the streaming potential method. At pH 7, the zeta potential of -58.5 mV for control fibers reduced with increase in the amount of acrylic acid (16.2%) and methacrylic acid (28.2%) grafts to -38.15 mV and -38.30 mV, respectively. The drop in the negative zeta potential value is attributed to rendering polypropylene hydrophilic. The acrylic acid graft was found to be more effective than the equivalent amount of methacrylic acid graft in this respect due to the different chemical characters of the two graft copolymers. The negative zeta potential was also reduced to a considerable extent when cationic dye solution was streamed through the grafted polypropylene fibers, which is attributed to the deposition of dye cations on the negatively charged surface of the grafted fibers. The results on surface charge density and surface conductivity also indicated the hydrophilic character of grafted polypropylene.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1984.070291005
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  • 9
    Electronic Resource
    Electronic Resource
    Radiation induced grafting of mixed monomers onto polyester and polypropylene fibers (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 33 (1987), S. 2707-2714 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Grafting of the mixture of acrylamide and acrylic acid onto polyester and polypropylene fibers and mixture of acrylic acid and methacrylic acid onto polypropylene by the radiation method are reported. It is observed that when pure acrylamide was used for grafting, the grafting extent was small, whereas when the mixture was used, the amount of acrylamide content in the copolymer was found to be more than the feed ratios. The results are explained on the basis of chain transfer mechanism. With methacrylic acid and acrylic acid mixtures, the rate of grafting decreased with the increase in the concentration of acrylic acid in the feed ratio, and this has been explained on the basis of the formation of either a 3-dimensional network structure or a highly branched structure involving backbone polymer molecules with acrylic acid, which prevents the diffusion of the monomer from the solution phase to the swollen phase.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1987.070330805
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  • 10
    Electronic Resource
    Electronic Resource
    Formation of ethylenediamine-cellulose complexes by vapor-phase treatment (1990)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 28 (1990), S. 21-23 
    Details
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1990.140280104
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