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  • 1990-1994  (5)
  • 1880-1889
  • Polymer and Materials Science  (5)
  • 1
    Electronic Resource
    Electronic Resource
    Extension of the measuring range in size exclusion chromatography to higher molar mass by use of a light scattering detectorDedicated to Professor Dr. Dr. h. c. mult. Otto Kratky on the occasion of his 90th birthday (1992)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 199 (1992), S. 7-14 
    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: Es wird eine neue Methode für die Erweiterung des Meßbereiches der Ausschlußchromatographie, gekoppelt mit Lichtstreuung (SEC/LALLS), zu höherer molarer Masse, vorgestellt. Diese Methode nützt den Effekt, daß das Lichtstreusignal oft schon bei wesentlich kleineren Werten des Elutionsvolumens, also hoheren Werten der molaren Masse erfaßbar ist als das Konzentrationssignal und berücksichtigt dabei die Peakverbreiterung in der SEC. Das betreffende Rechenverfahren wird für den Fall einer logarithmischen Normalverteiung und einer wahrscheinlichsten Verteilung getestet. Im Falle von Polypropylen mit logarithmischer Normalverteilung (M̄W = 420 000 und M̄n = 99 000) kann der durch SEC/LALLS erfaßte Bereich der molaren Masse um einen Faktor von ca. 10 erweitert werden; bei einer wahrscheinlichsten Verteilung (M̄n = 100 000) liegt die erreichbare Erweiterung des Meßbereiches der molaren Masse beieinem Faktor von ca. 2.
    Notes: A new method for the extension of the measuring range of size exclusion chromatography coupled with light scattering (SEC/LALLS) to higher molar mass is presented. This method uses the fact that the light scattering signal can often be detected already at considerable smaller values of the elution volume (i. e. higher values of molar mass) than the concentration signal; furthermore, it takes into account the peak broadening effect in SEC. This procedure is tested for the case of a logarithmic normal distribution and a most probable distribution of molar mass. In the case of polypropylene with a logarithmic normal distribution (M̄w = 420 000, M̄n = 99 000), the range of molar mass covered by SEC/LALLS can be extended by a factor of about 10; with a most probable distribution (M̄n = 100 000), the attainable extension in molar mass assumes a factor of about 2.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1992.051990102
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    The ene reaction between N-isobutylallylnadimide and N-isobutylmaleimide as a model for the cross-linking reaction in bis(allyl)nadimide polymerization (1990)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 191 (1990), S. 2579-2585 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction between N-isobutylallylnadimide (NIBANI) and N-isobutylmaleimide (NIBMI) was taken as a model reaction to obtain insight into the curing mechanism of polymeric alloys and composites consisting of bis- or tris(allyl)nadimides and bismaleimides. The reaction between NIBANI and NIBMI is not catalyzed by boron trifluoride etherate, neither at room temperature nor in refluxing methylene chloride. The thermally induced reaction (200°C) between NIBANI and NIBMI in equimolar quantities gives an indirect proof for the occurrence of an ene reaction. The high reactivity of the ene reaction product to undergo further Diels-Alder reaction was proved by GPC and direct inlet mass spectral studies.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1990.021911106
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  • 3
    Electronic Resource
    Electronic Resource
    Thermogravimetric study of nadic-, methylnadic-, and allylnadic-bisimide monomersDedicated to Prof. Dr. Klaus Hummel, Technical University of Graz, on the occasion of his 60th birthday. (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 929-931 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080290621
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  • 4
    Electronic Resource
    Electronic Resource
    Untersuchung der molmassenverteilung von harnstoff-formaldehyd-leimharzen durch GPC gekoppelt mit lichtstreuungHerrn Professor Dr. Gerd Greber zum 65. Geburtstag gewidmet (1990)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 180 (1990), S. 199-208 
    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: UF-resins have been synthesized with different degrees of condensation by different duration of the acidic condensation step and were characterized by gel permeation chromatography (GPC) on-line with a low angle laser light scattering (LALLS) photometer as molecular weight detector. The molar mass function lg Mw (V) and the weight average of molar mass have been calculated from the concentration signal and the scattering signal. The weight average molecular mass increases with longer condensation analogously to the turbidity temperature from several thousands up to more than 100000g/mol. Additionally it was found that UF-resins contain fractions with molar masses up to 500000g/mol which are not only aggregates caused by physical intermolecular forces.
    Notes: Es wurden UF-Harze mit verschiedenen Kondensationsgraden durch unterschiedlich lange saure Kondensation hergestellt und mittels Gelpermeationschromatographie (GPC), gekoppelt mit einem Kleinwinkel-Laserlichtstreugerät (LALLS), untersucht. Aus den Konzentrations- bzw. Lichtstreukurven kann die jeweilige Molmassenfunktion IgMw(V) sowie das Molmassengewichtsmittel berechnet werden. Dieses steigt mit fortschreitender Kondensation analog zur Trübungstemperatur der einzelnen Kondensationsstufe deutlich an und liegt im Bereich von einigen Tausend bis über 100000g/mol. Zusätzlich wurde festgestellt, daß in UF-Harzen Molmassen bis ca. 500000g/mol enthalten sind; dabei handelt es sich offensichtlich um Aggregate, die nicht nur durch physikalische Wechselwirkungen hervorgerufen werden.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1990.051800115
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  • 5
    Electronic Resource
    Electronic Resource
    Determination and correction of peak broadening in size exclusion chromatography of controlled rheology polypropylene (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 54 (1994), S. 47-55 
    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 peak broadening in size exclusion chromatography of seven commercial polystyrene (PS) standards with narrow molar mass distribution (MMD) and of 6-9 polypropylene (PP) fractions (M̄w/M̄n = 1.34-2.10) obtained by direct extraction was determined in four different column sets. The dependence of the Gaussian peak broadening parameter, σ2, on the peak elution volume was different for PS and PP. For a commercial grade of controlled rheology PP (CR-PP) (Daplen PT55) with M̄w/M̄n 〈 3 it was shown that disregard of the peak broadening effect leads to considerable errors in the MMD at low and higher molar mass and in the polydispersity parameter M̄w/M̄n. The same lot was studied in an Austrian National Research program for its physical propeties in processing and application and in a round-robin test of IUPAC working party IV.2.2. on molecular characterization of commercial polymers. © 1994 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070540105
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