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  • 1
    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: The elution behaviour in gel chromatography was investigated for a series of polystyrene, polyacrylonitrile and styrene acrylonitrile copolymer fractions with acrylonitrile contents of 12, 25 and 52% by weight. In each series of tests a separate calibration relationship for solutions in chloroform and dimethyl formamide (DMF) is obtained by plotting the molecular weight versus the elution volume. Using the hydrodynamic volume and undisturbed coil dimensions one can obtain universal calibration relationships, except for solutions of polystyrene in DMF. This exception is explained by the poor solubility of polystyrene in DMF, which necessitates taking into account the interaction between the polymer and solvent molecules. By plotting the product of the second virial coefficient and the molecular weight versus the elution volume a universal calibration relationship is obtained for all the differing series of solutions in chloroform; the differences between the solutions of polystyrene, the copolymers and polyacrylonitrile in DMF can be substantially reduced.
    Notes: An einer Reihe von Polystyrol-, Polyacrylnitril- und Styrol-Acrylnitril-Copolymerfraktionen mit 12, 25 und 52 Gew.-% Acrylnitril wurde das Elutionsverhalten in der Gelchromatographie untersucht. Durch Auftragen des Molekulargewichts über dem Elutionsvolumen erhält man in den Lösungsmitteln Chloroform und Dimethylformamid (DMF) für jede Probenreihe eine eigene Eichbeziehung. Bei Verwendung des hydrodynamischen Volumens und der ungestörten Knäueldimensionen erhält man universelle Eichbeziehungen mit Ausnahme von Polystyrol in DMF. Diese Ausnahme wird durch die schlechte Löslichkeit des Pölystyrols in DMF erklärt, die eine Berücksichtigung der Wechselwirkung zwischen Polymer und Lösungsmittelmolekülen erfordert. Es wird gezeigt, daß durch Auftragung des Produktes aus dem 2. Virialkoeffizienten des osmotischen Druckes und dem Molekulargewicht über dem Elutionsvolumen für alle unterschiedlichen Probenreihen in Chloroform eine universelle Eichbeziehung resultiert und die Unterschiede zwischen den speziellen Eichbeziehungen von Polystyrol, den Copolymeren und Polyacrylnitril in DMF wesentlich verringert werden.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 42 (1960), S. 151-157 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The electric polarization of a polymer is shown to depend upon the steric order along the chain. This is in accord with the previously observed electric polarization behavior of diastereomers. Solution measurements of the molar polarization of polymethyl methacrylates in benzene gave values of 32 ± 0.5 cc./mole for syndiotactic, and 41 ± 0.5 cc./mole for isotactic material, with atactic polymer showing intermediate values. It is believed therefore that the polarizability method can form a means of differentiating and interpreting the behavior of polar stereospecific polymers.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 31 (1959), S. 50-54 
    ISSN: 0009-286X
    Keywords: Chemistry ; Industrial Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Einige von Tigerschiöld und Rumpf angegebene Formeln für die Festigkeit von Pellets auf Grund von Kapillarkräften oder Salzbrücken werden an Preßlingen aus Tonerde nachgeprüft. Die Festigkeit ergibt sich als proportional zur Oberflächenspannug der Pelletisierungsflüssigkeit und umgekehrt proportional zur Korngröße, übereinstimmend mit der Theorie. Salzablagerungen findet man bevorzugt an der Oberfläche der Pellets, weil dort die Verdunstung am stärksten ist.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 1 (1963), S. 2207-2212 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Eighteen polyacene polymers were synthesized, and their resistivities were found to be of the order of 104-105 ohm-cm. The resistivity of these polymer semiconductors was found to be sensitive to changes in the conditions of synthesis, changes in the structure of the polymers, and variations of pressure and temperature during experimentation. The forbidden energy gap for these polymers was about 0.5 e.v. Although the formalism of the simple intrinsic semiconductor band model was not strictly applicable to the data on these polymers, such a treatment was found instructive.
    Additional Material: 1 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 40 (1907), S. 1303-1307 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 40 (1907), S. 1725-1730 
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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