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  • 1
    Electronic Resource
    Electronic Resource
    Die Abhängigkeit des Kontraktionsfaktors von der Molmasse bei Polyethylenen niederer Dichte (1980)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 31 (1980), S. 382-387 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: By means of elution fractionation and characterising the fractions by viscometry and GPC the lg gη vs. lg M dependences of 13 LD-PE samples are determined. The lg gη vs. lg M curves of the LD-PE obtained with a tubular reactor, contrarily to the LD-PE obtained with an autoclave, are stagelike in the range of molecular mass lower than 105 g/mol and have a different slope beyond 105 g/mol. Suggestions to explain the results are presented and the influence of this differences on measuring of molecular mass distribution by GPC is estimated.
    Notes: Die lg gη-lg M-Abhängigkeiten von 13 PE-ND-Proben wurden durch Elutionsfraktionierung und Charakterisierung der Fraktionen mittels Viskosimetrie und GPC bestimmt. Ethylenpolymerisate nach dem Rohrreaktorverfahren zeigen im Gegensatz zu Polymeren nach dem Autoklavenverfahren einen stufenförmigen Verlauf der lg gη-lg M-Abhängigkeit im Molmassenbereich unter 105 g/mol sowie einen unterschiedlichen Abfall des gη-Wertes über 105 g/mol. Es werden Vorschläge zur Erklärung der Befunde gemacht und die Auswirkungen dieser Unterschiede auf die Bestimmung der MMV durch GPC abgeschätzt.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1980.010310609
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  • 2
    Electronic Resource
    Electronic Resource
    Radiolysis of polymers of chlorine methacrylates (1988)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2669-2681 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymers of α-chloroacrylate (MCA), 1-chloroethyl methacrylate (1CEMA), 2-chloroethyl methacrylate (2CEMA), 2,2,2-trichloroethyl methacrylate (trCEMA) and 1,2,2,2-tetrachloroethyl methacrylate (teCEMA) were γ-irradiated at 77 K. The primary radicals were generated by the abstraction of chlorine. They decay or change into chain end radicals upon warming up to room temperature.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1988.080261004
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  • 3
    Electronic Resource
    Electronic Resource
    Radiation induced radical reactions in poly(chloroalkyl methacrylate)s/triallylisocyanurate mixtures (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 1589-1598 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Radical generation after γ-irradiation at 77 K and radical reactions during temperature increase are discussed for the polymers poly(2-chloroethyl methacrylate) and poly(1,2,2,2-tetrachloroethyl methacrylate), mixed with triallylisocyanurate (TAIC). After the radiation interaction radicals are generated in the ester alkyl side groups of the polymer by chlorine abstraction in both polymer/TAIC mixtures. Radical transfer to TAIC occurs during temperature increase to produce allyl radicals. Hence, the high radiation sensitivity of chlorine-containing polymers is combined with the reactivity of allyl radicals of TAIC in such polymer-TAIC mixtures.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270510
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  • 4
    Electronic Resource
    Electronic Resource
    Radikalreaktionen in γ-bestrahltem Polymethylmethacrylat (1985)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 36 (1985), S. 162-166 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The reactions of radicals formed by 60Co irradiation in poly(methyl methacrylate) and copolymers of methyl methacrylate and methacrylic acid (70/30) have been investigated. Further radical formation was found to occur with increasing temperature, amounting to 10% of the radical formation by γ-radiolysis. The validity of the model of a wide distribution of reaction rates is discussed.
    Notes: Die Reaktionen der Radikale, die durch 60Co-Strahlung in Polymethylmethacrylat und in Copolymerisaten aus Methylmethacrylat und Methacrylsäure (70/30 Masse-%) erzeugt werden, wurden untersucht. Es wird nachgewiesen, daß durch Temperaturerhöhung weitere Radikale erzeugt werden, die 10% der durch γ-Radiolyse gebildeten Radikalkonzentrationen erreichen. Die Anwendbarkeit des Modells der breiten Verteilung der Reaktionsgeschwindigkeiten wird diskutiert.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1985.010360310
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  • 5
    Electronic Resource
    Electronic Resource
    EPR studies during radical polymerization in the liquid state. Review (1981)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 32 (1981), S. 491-511 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Möglichkeiten und Grenzen, EPR-spektroskopisch tiefergehende Erkenntnisse über die Elementarprozesse der Radikalbildung und der Polymerisation zu gewinnen, werden vorgestellt. Die Darstellung erfolgt hauptsächlich an Hand von Messungen an kurzlebigen Radikalen, die in der Startphase der Vinylpolymerisation und -copolymerisation und während der Photolyse von Maleinsäureanhydrid-Lösungen auftreten. Berichtet wird über chemische und sterische Radikalstrukturen, über innermolekulare und Gesamt-Bewegung freier Radikale, über zwischenmolekulare Wechselwirkungen in Polymerisationslösungen, über die Erforschung von Reaktionsmechanismen und von Vorgängen im Elektronenspinsystem (CIDEP) mittels stationärer und zeitaufgelöster EPR sowie über die Ermittlung von Reaktionsgeschwindigkeits-Konstanten.
    Notes: This paper deals with the possibilities and limitations of obtaining data on the elementary processes of radical formation and polymerization. As examples were especially discussed measurements carried out during the initial reactions of vinyl polymerization and copolymerization and during the photolysis of maleic anhydride solutions. Chemical and steric radical structures, internal and external motion of free radicals, intermolecular interactions in polymerizing solutions, the investigation of reaction mechanisms and of processes in the electron spin system (CIDEP) by stationary and time-resolved EPR as well as the determination of rate constants of chemical reactions are reported.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1981.010320901
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  • 6
    Electronic Resource
    Electronic Resource
    ESR-untersuchungen an γ-bestrahltem polymethylmethacrylat und an einem copolymerisat mit methacrylsäure (1985)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 36 (1985), S. 268-272 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Based on ESR data the effect of annealing and oxygen on the radical reactions in γ-irradiated copolymers of methacrylic acid methyl ester and methacrylic acid is compared with the effect in poly(methyl methacrylate).
    Notes: Der Einfluß von Temperung und Sauerstoff auf die Radikalreaktionen in γ-bestrahlten Copolymeren aus Methacrylsäuremethylester und Methacrylsäure werden im Vergleich zu denjenigen in Polymethylmethacrylat ausgehend von ESR-Messungen diskutiert.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1985.010360509
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  • 7
    Electronic Resource
    Electronic Resource
    Die Beziehung zwischen Grenzviskositätszahl und Schmelzindex bei unter hohem Druck hergestellten Ethylenpolymerisaten (1980)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 31 (1980), S. 414-418 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The position of straight lines of viscosities in the lg MI vs. [η] representation depends on the structure of branching. By discussion of the individual dependences MI = f(ḡη) and [η] = f(ḡη) at constant reduced molecular weight \documentclass{article}\pagestyle{empty}\begin{document}$ \left( {\overline {M \cdot g_\eta } } \right)_\omega $\end{document} the position of straight lines is an unambiguous function of ḡη and by it of the long chain branching also with regarding the HD-PE.
    Notes: Die Darstellung der Viskositätskennwerte in einem lg SI-[η]-Koordinatensystem ergibt Geraden, deren Lage von Parametern der Verzweigungsstruktur abhängt. Durch Betrachtung der Einzelabhängigkeiten SI = f(ḡη) und [η] = f(ḡη) bei konstanter reduzierter Molmasse \documentclass{article}\pagestyle{empty}\begin{document}$ \left( {\overline {M \cdot g_\eta } } \right)_\omega $\end{document} kann die Lage der Geraden auch unter Einbeziehung des PE-HD als eindeutige Funktion von ḡη und damit vom Langkettenverzweigungsgrad erklärt werden.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1980.010310703
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  • 8
    Electronic Resource
    Electronic Resource
    ESR investigations of peroxide radicals in γ- and electron irradiated FEP filmsDedicated to Professor Dr. habil. Christian Ruscher on occasion of his 60th birthday. (1988)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 39 (1988), S. 183-186 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In einem Copolymer aus Tetrafluorethylen und Hexafluorpropylen (FEP) wurden Kettenendperoxidradikale durch γ- und Elektronenbestrahlung im Vakuum und nachfolgende Oxidation mit Luftsauerstoff erzeugt. Zwischen 93 K und 293 K wurdeu reversible Änderungen der ESR-Spektren in Abhängigkeit von der Temperatur registriert. Die mit beiden Strahlungsarten erzeugten Spektren stimmen gut überein. Nach Temperung bei 343 K erhält man ein Peroxidradikal höherer Beweglichkeit. Die Spektren dieses Radikals konnten mit modifizierten BLOCHschen Gleichungen unter Verwendung eines „kubischen Sprungmodells“ für die Radikalbewegung simuliert werden. Die Aktivierungsenergie beträgt 4,2 kJ/mol.
    Notes: End chain peroxide radicals were generated in a copolymer of tetrafluoroethylene and hexafluoropropylene (FEP) by γ- and electron irradiation in vacuo and subsequent exposure to air. Reversible temperature changes of ESR spectra were recorded in the range from 93 K to 293 K. There is a good agreement between the spectra obtained by the two methods of irradiation. After annealing at 343 K a peroxide radical species of higher mobility remains. The spectra of this species can be simulated by using modified Bloch equations with a “cubic jump” model for motion. The activation energy is 4.2 kJ/mol.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1988.010390409
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