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  • 1960-1964  (3)
  • 1
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 42 (1960), S. 165-171 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The intensities of x-ray reflections from ordered regions of Cellulose I (ramie) an Cellulose II (Fortisan) have been determined by photometering the x-ray diagrams. The results are reported as intensities of resolvable reflections, to provide a basis for comparison with postulated crystal structures to be described in Part V of this series. In many cases reflections from several crystallographic planes could not be resolved and the total intensity for the group of reflections is given. This procedure does not make full use of the experimental results; the factors which would have to be taken into account in a more complete interpretation of the data are discussed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 60 (1962), S. 1-20 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A microbeam x-ray diffraction method has been used to study orientation in spherulites grown from the melt of nylon 66 and in one case of nylon 610. It is concluded that in positively birefringent spherulites the crystallographic a axis is parallel to the spherulite radius. The zigzag extinction pattern shown by such spherulites in a polarizing microscope can be understood in terms of this orientation. The results on negatively birefringent spherulites are not in agreement with earlier results of Keller and it is suggested that further work on such spherulites is desirable. Evidence is cited which shows that zero birefringent spherulites have random orientation. The spheruloids or spheruloidal aggregates which grow at the same time as negatively birefringent spherulites are found to have well defined optical properties when grown in thin films and confused optical properties when grown in thick film. This difference is reflected in differences in the x-ray diagrams. In thin films a unique orientation exists in which a direction close to the crystallographic b axis lies parallel to the radius while the (002) plane lies near the surface of the film. This orientation provides an explanation of the observed optical properties. In thick film the (002) plane again tends to lie near the surface of the film, but orientation relative to the radius varies from place to place, thus causing confused optical properties.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 1 (1963), S. 671-685 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Observations on the x-ray scattering by ball-milled cellulose and cellulose derivatives, amorphous oligosaccharides, and Fortisan H are reported and an approximate shape is established for the scattering curve of the noncrystalline component of celluloses. Using this shape measurements have been made of the minimum crystallinity which is consistent with the observed x-ray diagram of regenerated cellulose.From a comparison of this minimum crystallinity with crystallinity determined by the infrared-deuteration method, it is concluded that at least 14% of the total material cannot be truly described as either perfectly crystalline or perfectly amorphous. This fraction of material of intermediate order is registered as crystalline by x-ray diffraction, but infrared spectroscopy suggests that it does not possess the precise molecular configuration characteristic of crystalline material. Support for this view of structure is reported from observations of differences in hydrogen-bonding in amorphous regions of regenerated and bacterial celluloses. Infrared results show that OH groups which lie in the surface of crystallites are hydrogen-bonded in a random amorphous manner and it is concluded that the material of intermediate order can be accounted for in terms of chains lying in the surface of crystallites of cross-section 29 A. × 65 A.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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