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  • 1
    Electronic Resource
    Electronic Resource
    Studies on cellulose acetate phthalate: Estimation of mark-houwink-kuhn-sakurada constants and viscosity-temperature relationship (1991)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 188 (1991), S. 41-49 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Celluloseacetatphthalat (CAP) mit einem Acetylgehalt von 19,5 Gew.-% und einem Phthalylgehalt von 21,4 Gew.-% wurde hergestellt und durch fraktionierte Fällung in fünf Fraktionen mit gleichmäßig abnehmendem Molekulargewicht aufgetrennt. Die Werte für das zahlenmittlere Molekulargewicht (M̄n) dieser Fraktionen wurden membranosmometrisch in 0,05 N NaHCO3 gemessen; die Werte für die Grenzviskosität ([η]) wurden ebenfalls von allen fünf Fraktionen bei verschiedenen Temperaturen bestimmt. Die Beziehung zwischen [η] und M̄n wurde nach der Mark-Houwink-Kuhn-Sakurada-Gleichung ausgewertet, und aus den dabei erhaltenen Werten für v zeigte sich, daß CAP offensichtlich ein sehr steifes Polymeres ist. Die Temperaturabhängigkeit der Viskosität verdünnter CAP-Lösungen wurde nach der Methode von Moore durch einen Arrhenius-Ausdruck beschrieben. Die Aktivierungsenergie der Durchflußgeschwindigkeit hängt sowohl von der Konzentration als auch vom Molekulargewicht ab; aus dem dabei erhaltenen empirischen Parameter Ke kann ebenfalls auf ein steifes Polymeres geschlossen werden.
    Notes: Cellulose acetate phthalate (CAP) having an acetyl content of 19.5 wt.-% and a phthalyl content of 21.4 wt.-% was prepared and fractionated into five fractions of regularly decreasing molecular weight. The values of the number average molecular weight (M̄n) of these fractions were measured in 0.05 N NaHCO3 by the help of high-speed membrane osmometer. The intrinsic viscosity [η] values for all the fractions of CAP in 0.05 N NaHCO3 were also determined at different temperatures. The Mark-Houwink-Kuhn-Sakurada equation was applied to the obtained results and the [η]-M̄n relationships for CAP have been established. The results of the values of v suggest that CAP is a stiff polymer. The temperature dependence of the viscosity of dilute CAP solutions has been described by an Arrhenius expression according to Moore's treatment. The activation energy of flow was found to depend on both concentration and molecular weight through an empirical parameter (Ke). The Ke value obtained for CAP also indicates that CAP is a rigid polymer.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1991.051880104
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  • 2
    Electronic Resource
    Electronic Resource
    Grafting of different vinyl monomers onto sodium salt of partially carboxymethylated amylose (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 210 (1993), S. 1-5 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Acrylnitril (AN), Methylacrylat (MA), Ethylacrylat (EA), Methylmethacrylat (MMA), Butylacrylat (BA) und Vinylacetat (VAc) wurden radikalisch unter Verwendung von Cerammoniumnitrat als Initiator auf das Natriumsalz von partiell carboxy-methylierter Cellulose gepfropft. Dabei wurde folgende Reihenfolge der Reaktivitäat gefunden: AN 〉 MA 〉 EA 〉 MMA 〉 BA 〉 VAc.
    Notes: In order to study the reactivity of different vinyl monomers, the grafting of different vinyl monomers such as acrylonitrile (AN), methylacrylate (MA), ethylacrylate (EA), methyl methacrylate (MMA), butylacrylate (BA) and vinyl acetate (VAc) onto the sodium salt of partially carboxymethylated amylose (DS = 0.313) has been carried out using ceric ammonium nitrate as an initiator. The following reactivity order of monomers has been found: AN 〉 MA 〉 EA 〉 MMA 〉 BA 〉 VAc.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052100101
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal behaviour of graft copolymers of sodium alginate (1996)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 235 (1996), S. 1-13 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die thermische Stabilität von Natriumalginat (SA) und dessen Pfropfcopolymeren mit Acrylnitril (AN), Methylacrylat (MA) und Ethylacrylat (EA) sowie Methylmethacrylat (MMA) wurde thermogravimetrisch in Luft untersucht. Aus den charakteristischen Abbautemperaturen ergibt sich die Stabilitätsreihenfolge SA-g-PAN 〉 SA-g-PMA 〉 SA-g-PEA 〉 SA-g-PMMA. Ein Vergleich der Abbau-Aktivierungsenergien ergab die gleiche Reihenfolge.
    Notes: The thermal stability of sodium alginate (SA) and its graft copolymers of acrylonitrile (AN), methyl acrylate (MA), ethyl acrylate (EA) and methyl methacrylate (MMA) has been examined in air atmosphere by means of thermogravimetric analysis. The following order of decreasing stability was found from characteristic decomposition temperatures: SA-g-PAN 〉 SA-g-PMA 〉 SA-g-PEA 〉 SA-g-PMMA. The overall thermal stability of the different SA graft copolymers was evaluated by comparing their activation energies of thermal degradation; it agreed with the same order of thermal stability.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1996.052350101
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  • 4
    Electronic Resource
    Electronic Resource
    Ceric-induced grafting of ethyl-acrylate onto sodium alginate (1994)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 214 (1994), S. 75-89 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ethylacrylat wurde in Gegenwart von Cerammoniumnitrat als Initiator auf Natriumalginat gepfropft. Die Konzentrationen von Salpetersäure, Initiator und Monomerem sowie Reaktionszeit und -temperatur und die Substratmenge wurden zur Ermittlung der günstigsten Pfropfbedingungen variiert. Ein kinetisches Modell der radikalischen Pfropfcopolymerisation und Gleichungen füur die Beschreibung der Geschwindigkeiten der Homopolymerisation, der Copolymerisation und der Gesamtpolymerisation werden vorgeschlagen. Die experimentellen Daten stimmen sehr gut mit dem vorgeschlagenen kinetischen Modell überein.
    Notes: Sodium alginate was graft-copolymerized with ethyl acrylate using ceric ammonium nitrate as an initiator. In order to optimize the conditions for grafting, the concentrations of nitric acid, initiator and monomer together with temperature, time and amount of substrate were varied. The kinetic scheme of free radical graft copolymerization has been proposed and the equations relating the values of rate of polymerization, rate of graft copolymerization and rate of homopolymerization are also suggested. The experimental results agree very well with the proposed kinetic scheme.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1994.052140108
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  • 5
    Electronic Resource
    Electronic Resource
    Fenton's reagent-initiated graft copolymerization of acrylonitrile onto sodium alginate (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 51 (1994), S. 1421-1426 
    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: Graft copolymerization of acrylonitrile (AN) onto sodium alginate was studied in an aqueous medium using ferrous ammonium sulfate-hydrogen peroxide (Fenton's reagent) as the redox initiator. To optimize the reaction conditions for affording maximum percentage of grafting, the concentrations of sulfuric acid, initiator components, monomer, and also temperature and time were varied. The results are discussed and a reaction mechanism is proposed. © 1994 John Wiley & Sons, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070510809
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