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  • Physics  (2)
  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 4 (1966), S. 611-629 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Epitaxial deposition of homopolymers from solution [polyethylene, isotactic polystyrene, poly-3,3-bischloromethyloxacyclobutane (Penton) and polypropylene] was found on the (001) faces of cleaved alkali halide single crystals. Electron and optical microscopy studies have shown that the polymer usually grew from small, rodlike crystallites which were oriented in (110) directions of the halide crystal. Large oriented, four-leaved, “rose” structures also were observed for polyethylene. Electron diffraction studies indicate that the polymer chain axes for polyethylene, isotactic polystyrene, and Penton generally lie parallel to the (001) faces of the halide crystal and are also oriented in the 〈110〉 directions of the crystal face. Investigations on the effect of various halide substrates upon the epitaxial crystallization habit of polyethylene inferes that lattice matching does not play the major role in orientation. Two possible explanations are offered for this epitaxial behavior.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The small-angle x-ray scattering (SAXS) from an Epon 812 and two Epon 828 (one amine-cured and one anhydride-cured) epoxy resins has been measured using a Bonse-Hart system. The data cover the angular range (2θ) between 20 sec and 60 min. After correction for absorption, background and vertical beam divergence, they have been placed on an absolute basis by comparison with the scattering from a previously studied polycarbonate sample. The corrected absolute intensity decreases strongly with increasing angle between 20 sec and 2 min, decreases more gradually between 2 and 20-30 min, and reaches a nearly constant asymptotic value at larger angles. The magnitude of the intensity in the constant-intensity region is close to the value predicted by thermodynamic fluctuation theory for fluids applied at the glass transition temperature. The increase in intensity at angles smaller than 20-30 min is associated with heterogeneities in the cured resins. These heterogeneities cover a range of sizes in all samples, from less than 100 Å to more than 1000 Å, with the most frequently occurring size in the range 100-200 Å.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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