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  • Polymer and Materials Science  (8)
  • Engineering General  (1)
  • 1
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: The addition of mercaptoethanol and hydrogen sulfide to the pendent double bonds of acrylamidomethylated cotton (AMC) has been investigated. The interaction of acrylonitrile with the modified celluloses so obtained (substrate I and II) and with AMC treated with ammonium hydroxide (substrate III) in the presence of Ce(IV) is studied. Substrate I shows higher initial grafting yields. than AMC; the opposite holds true for the maximum graft yields. The graft yields obtained with substrate II are lower than those of AMC. All modified cottons studied are less amenable to grafting compared with the unmodified cotton. The graft yields of AMC and substrate III are comparable due to the fact that both substrates are crosslinked. Probable reasons for the inferior reactivity of substrates I and II are also given.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    ISSN: 0003-3146
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Gebeiztes Baumwollgarn (Substrat I) wurde spannungslos mercerisiert (Substrat II) und spannungslos mercerisiert, dann verstreckt um 94% (Substrat III) und 103% der urspriinglichen Länge (Substrat IV). Diese Substrate wurden einer Säurevorbehandlung unterworfen (0,5 N HCl, 60°C, 15 min). Die vier Substrate und ihre entsprechenden HCl-behandelten Substrate (I-H, II-H, III-H und IV-H) wurden unter ähnlichen Bedingungen mit N,N-Diethylaziridinchlorid umgesetzt, um Diethylaminoethyl (DEB)-Baumwolle zu erhalten. Zusätzlich wurden DEAE-Baumwollproben der Substrate I, I-H, II und II-H mit 0,5 N HCl bei 80°C 0,5, 1,2,3,5 und 7 h hydrolysiert und das Verhältnis der Substituenten in den D-Glucopyranosyl-Einheiten dieser DEAE-Baumwollproben sowie in denen der DEAE-Hydrocellulosen wurde bestimmt. Es wurde gefunden, daß ein beachtlicher Unterschied zwischen der Reaktivität gebeizter und spannungslos mercerisierter nachverstreckter Baumwolle besteht. Dies wurde im Sinne von Unterschieden in der Mikrostruktur der verschiedenen Substrate interpretiert, die umgekehrt Verfügbarkeit, Zugänglichkeit und Ordnungszustand der Cellulose-Hydroxylgruppen in gebeizter und mercerisierter Baumwolle widerspiegeln. Stickstoff-, chemische, mikroskopische und Röntgenanalysen wurden benutzt, um die strukturellen Unterschiede zwischen den Substraten festzustellen.
    Notizen: Scoured ply cotton yarn (substrate I) was slack mercerized (substrate II) and slack mercerized followed by stretching to 94% (substrate III) and 103% of original length (substrate IV). These substrates were given an acid pretreatment (0.5 N HCl, 60°C, 15 min). The four substrates and their corresponding HCl-treated substrates (substrates I-H, II-H, III-H and IV-H) were reacted under similar conditions with N,N-diethylaziridinium chloride to yield diethylaminoethyl (DEAE)-cottons. In addition, DEAE-cottons of substrates I, I-H, II and II-H were hydrolyzed with 0.5 N HCl at 80°C for 0.5, 1, 2, 3, 5 and 7 h and the ratio of substituents in the D-glucopyranosyl units of these DEAE-cottons as well as in those of DEAE-hydrocelluloses were determined. It was found that there is a considerable difference between the reactivity of scoured cotton and slack mercerized-restretched cottons. This was interpreted in terms of differences in the microstructure between the substrates in question, which in turn, are reflected on availability, accessibility and state of order of the cellulose hydroxyls in the scoured and mercerized cottons. Nitrogen-, chemical, microscopical and X-ray analyses were used to assess the structural differences among the substrates.
    Zusätzliches Material: 7 Tab.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 20 (1976), S. 2407-2418 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Viscose rayon fibers modified with polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) were dyed with some direct and reactive dyes. Exhaustion rate of the dye onto fibers was governed by the amount and nature of the polymer grafted. In general, the dye affinity for cellulose and dye exhaustion onto fibers decreased as the graft yield increased. Dye affinity for the PAN-cellulose graft copolymers was greater than that found with PMMA-cellulose graft copolymers. Except in a few cases, the tendency of cellulose graft copolymers of ca. 13% graft to accept direct dyes was more than that of the untreated cellulose, whereas the affinity of reactive dyes for cellulose graft copolymers of up to ca. 43% polymer was more than that of untreated cellulose. The dye fixation, based on the weight of cellulose component, increased as the graft yield increased. The dyeability of cellulose oxidized with ceric ammonium nitrate was also examined. Oxidation of cellulose prior to dyeing reduced the affinity of the dye for cellulose.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 4
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 24 (1979), S. 2071-2072 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Partial carboxymethylation of the cotton component of polyester/cotton blend prior to durable press finishing with dimethyloldihydroxyethylene urea in presence of MgCl2·6H2O was carried out under different conditions to control the carboxyl content as well as alteration of the blend components accompanying the chemical modification. The susceptibility of these modified blend samples before and after crosslinking to aqueous and nonaqueous oily soiling and their ability to release the soil was examined. The general indications are that introduction of carboxymethyl groups in the molecular structure of the cotton component of the blend imparts soil release characteristics of the blend provided that (a) the condition of partial carboxymethylation is not accompanied by profound changes in neither the microstructure of the cotton component nor in the polyester content of the blend and (b) the carboxymethyl content should not be so high. It is proposed that the anionic nature of the modified cotton component of the blend during washing helps in repelling the negatively charged soil particles from the blend surface. In addition, a reduction in the interfacial tension at the soil-water interface assists in rolling up the soil and subsequent removal. This can be turned to the opposite if the electrostatic repulsion is masked through creation of soft swollen environment by significantly increasing the carboxymethyl content, decreasing the polyester content, and/or increasing the swellability of cotton component of the blend.
    Zusätzliches Material: 10 Tab.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 17 (1973), S. 2725-2738 
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Acrylamidomethylated cellulose (AMC) was prepared by reacting cellulose with N-methylolacrylamide or its ethers in acidic medium under a variety of conditions. The extent of the reaction, expressed as mmole double bonds per 1 g cellulose, increased by increasing the concentration of N-methylolacrylamide or its ethers. However, the paddry-cure technique produced AMC with greater amounts of double bonds than the pad-batch technique. Also, the reactivity of the etherifying agents follow the order N-methylolacrylamide〉N-methoxymethylacrylamide〉N-methoxymethylmethacrylamide. Furthermore, the behavior of AMC in neutral, alkaline, and acidic media was studied. No change in the amount of the pendent double bonds of AMC occurred in neutral medium regardless of the conditions employed. On the contrary, disappearance of the double bonds took place in alkaline medium. The extent of disappearance depends on the kind of alkali used as well as on the conditions implemented. It was disclosed that consumption of the pendent double bonds of AMC occurred mainly via addition of the cellulose hydroxyls to yield a crosslinked cellulose. Treatment with hydrochloric acid, on the other hand, resulted in partial splitting of the acrylamidomethyl groups as well as addition of the acid on the pendent double bonds of AMC.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    ISSN: 0323-7648
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Der Einfluß von Carbamoylethylgruppen, die in die Molekülstruktur der Cellulose im wäßrigen bzw. nahezu nichtwäßrigen Medium eingeführt wurden, auf das Anschmutz- und Schmutzentfernungsverhalten von Baumwollgeweben mit und ohne Knitterfestausrüstung wurde untersucht. Wäßriger und nichtwäßrig-öliger Schmutz wurde angewendet. Die Carbamoylethylierung verringert die Aufnahmefähigkeit der Baumwolle für beide Schmutztypen, wobei die im wäßrigen Medium durchgeführte Carbamoylethylierung wirksamer ist als die im nichtwäßrigen Medium. Die Vernetzung setzt den Widerstand der carbamoylethylierten Baumwolle gegen die Anschmutzung herab.
    Notizen: The effect of introducing carbamoylethyl groups in the molecular structure of cotton cellulose under aqueous and almost nonaqueous condition on the soiling and soil release properties of cotton fabrics before and after durable press treatments was investigated. Aqueous and nonaqueous oily soils were used. Carbamoylethylation decreased the susceptibility of cotton to aqueous as well as nonaqueous oily soils. Aqueous carbamoylethylation improves the soil resistance more than the almost nonaqueous carbamoylethylation. Crosslinking decreases the resistance of carbamoylethylated cotton to soiling.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    ISSN: 0323-7648
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Das Anschmutz- und Schmutzentfernungsverhalten von cyanoethylierten Baumwollgeweben mit und ohne Knitterfestausrüstung wurde untersucht. Die Cyanoethylierung der Baumwolle verbesserte den Widerstand gegenüber wäßrigen und nichtwäßrig-öligen Anschmutzungen. Diese Eigenschaft bleibt auch nach einer Knitterfestausrüstung des Gewebes erhalten. Eine teilweise Umwandlung der Cyanoethylgruppen in Carboxyethylgruppen bewirkt eine weitere Verbesserung des Widerstandes gegen wäßrige Anschmutzung, beeinträchtigt aber das Verhalten gegen nichtwäßrig-öligen Schmutz, insbesondere nach der Knitterfestbehandlung.
    Notizen: The soiling and soil release properties of cyanoethylated cotton fabrics with and without durable press treatment were examined. Cyanoethylation of cotton improved its resistance to aqueous and nonaqueous oily soiling. The same situation is encountered after durable press treatments. Partial conversion of the cyanoethyl groups to carboxyethyl groups caused further enhancement in aqueous soil resistance but impairs nonaqueous oily soil resistance, particularly after the durable press treatment.
    Zusätzliches Material: 5 Tab.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 9
    Digitale Medien
    Digitale Medien
    Chichester [u.a.] : Wiley-Blackwell
    International Journal for Numerical Methods in Engineering 29 (1990), S. 833-846 
    ISSN: 0029-5981
    Schlagwort(e): Engineering ; Engineering General
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Mathematik , Technik allgemein
    Notizen: A non-Jacobian numerical quadrature is proposed for evaluating improper integrals over a semi-infinite range. The quadrature first transforms the semi-infinite integration limit into a finite limit between - 1 and 1. Standard numerical integration procedures such as Gauss-Chebyshev or Gauss-Legendre schemes can then be used to obtain the integral value. Unlike traditional methods using Laguerre or Hermite polynomials, numerical results show that no specific weight function is required for the proposed quadrature to converge as long as the integral exists. The transformation also includes a scale parameter which effectively expands the numerical-integration sampling points along its original semi-infinite integration path. Numerical examples shows that selection of the scale parameter is rather flexible and convergence can always be achieved within a wide range of parameter values. Several applied mechanics problems are also illustrated to validate the proposed numerical scheme. The quadrature can be easily incorporated into finite element or boundary element schemes for the evaluation of semi-infinite integrals.
    Zusätzliches Material: 10 Ill.
    Materialart: Digitale Medien
    Standort Signatur Einschränkungen Verfügbarkeit
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