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  • 1
    Electronic Resource
    Electronic Resource
    Characterization of ethylene-propylene block copolymers by proton magnetic resonance (1966)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 189-195 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A high-resolution proton magnetic resonance compositional analysis has been developed for propylene polymers containing 0-40 wt.-% ethylene as either homopolymer or copolymer blocks. The test is independent of tacticity and provides qualitative information on copolymer sequencing and propylene chain structure. The analysis was developed using a series of standard reference polymers synthesized to contain various ratios of C14-tagged ethylene and propylene. The compositional standards were established by radiotracer analysis for C14 and by preparing weighed physical mixtures of homopolymers. Spectra were obtained at 200 ± 10°C. by placing externally heated polymer solutions into a conventional probe of a Varian A-60 proton spectrometer. All measurements were made on ± 10% polymer solutions in diphenyl ether. Analyses are accurate to about ± 10% at higher ethylene concentrations. The method is sensitive, with less precision, to below 1% for ethylene either as blocks or homopolymer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1966.150040112
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  • 2
    Electronic Resource
    Electronic Resource
    Method of calibrating gel permeation chromatography with whole polymers (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1391-1394 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Column systems for gel permeation chromatography are usually calibrated by eluting a series of sharp polymer fractions of known molecular weights and by correlating their elution volumes with molecular size or weight. A different method for calibration is proposed in which only one polymer sample, with a broad, well-characterized molecular weight distribution, is used. The cumulative distribution and the integrated, normalized GPC chromatogram are successively superimposed, and molecular weights and corresponding elution volumes are correlated. It is found that calibration curves obtained in this manner show a definite curvature. A possible explanation and correction for this behavior is given, based on the concentration dependence of elution volumes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150050619
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  • 3
    Electronic Resource
    Electronic Resource
    Effect of temperature and polymer type on gel permeation chromatographyPart X in a series of papers on column fractionation of polymers. (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 987-991 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A series of polyisobutene and polystyrene fractions was subjected to gel-permeation chromatography at 150°C. The two types resulted in distinctly different calibration curves in a plot of projected, extended chain length versus elution volume. The average end-to-end distances of the samples were determined by intrinsic viscosity measurements. It was found that these data plotted versus elution volume could be represented by a common curve for both polymer types. The elution volumes of the polyisobutene series were determined at three additional temperatures, 35, 70, and 110°C. It could be shown that elution volume is again determined by polymer coil size at the temperature of measurement.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150050504
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