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  • 11
    Electronic Resource
    Electronic Resource
    Some studies of the crystallization of polychlorotrifluoroethylene copolymer films (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 31-61 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A fluorocarbon copolymer of chlorotrifluoroethylene (96%) and vinylidene fluoride has been isothermally crystallized and the quenched films analyzed by the light microscope, photographic light-scattering, and density measurements. Above a supercooling of 79°C., homogeneous nucleation dominates, giving a morphology that appears to be that of a twisted ribbon. At supercoolings below 79°C., heterogeneous nucleation dominates and leads to spherulitic morphology. Sheaf or rodlike morphology occurs at very low supercoolings. Crystallization rates determined from density measurements at room temperature indicate maximum rate due to heterogeneous nucleation occurring at a supercooling greater than 79°C., but the temperature for maximum rate cannot be identified because of the transition to homogeneous nucleation which causes a discontinuity in the rate versus temperature curve. Superposability of crystallization isotherms constructed from density values are inconsistent with the large melting point lowering from that of polychlorotrifluoroethylene for this copolymer. However, this may be explained by the presence of a different crystal system for each monomer in the copolymer.
    Additional Material: 25 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160060102
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  • 12
    Electronic Resource
    Electronic Resource
    Effect of birefringence on low-angle light-scattering patterns from oriented polymer films (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 271-278 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of birefringence of a polymer film upon its photographic light-scattering pattern is considered for the case of a single, anisotropic, two-dimensional spherulite imbedded in a birefringent matrix. It is shown that for the case of a polarizer and analyzer crossed at +45° and -45° to the analyzer, the scattering pattern is modified in a manner agreeing with experimental observation.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1969.160070202
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  • 13
    Electronic Resource
    Electronic Resource
    Low-angle light-scattering equations for polymer spherulites (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1147-1148 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090610
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  • 14
    Electronic Resource
    Electronic Resource
    Stress-optical coefficient of poly-1,4-butadienes (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1417-1447 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The stress-optical coefficient of poly-1,4-butadiene is measured as a function of strain, cis/trans ratio, and degree of swelling. Deviations from the Kuhn-Grün theory are found which are reduced upon swelling. Results are interpreted in terms of the Shindo-Stein theory of birefringence of polymers containing statistical segments of different sizes. This interpretation for the unswollen polymer leads to the unreasonable conclusion that the cis segment is considerably longer than the trans. Reinterpretation for the swollen polymer leads to the more reasonable conclusion that the trans segment is slightly longer than the cis. The dependence of the stress-optical coefficient on the nature of the swelling solvent is similar to the observations of Gent and Nagai and is believed to result from the effect of internal field from anisotropic solvent molecules. It is felt that the value of the stress-optical coefficient for the dry rubber is modified by the internal field from somewhat locally ordered neighboring polymer molecules.
    Additional Material: 22 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090805
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  • 15
    Electronic Resource
    Electronic Resource
    Effect of optical rotation on low-angle light-scattering patterns (1970)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 8 (1970), S. 1491-1502 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of optical rotation of the environment is calculated for the Hv and Vv low-angle light-scattering patterns of two-dimensional spherulites. As with the effect or birefringence, the change in the Hv pattern is greater than that of the Vv pattern. With increasing optical rotation, the patterns lose their characteristic shape and become more circular.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1970.160080906
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  • 16
    Electronic Resource
    Electronic Resource
    Small-angle light scattering by random assemblies of incomplete spherulites. I. Sheaflike textures (1970)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 8 (1970), S. 2115-2126 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The calculation of the scattering from a sheaflike sector of a two-dimensional spherulite has been carried out as a function of the apex angle of the sector. It is found that while for a complete spherulite the Hv scattered intensity is zero at zero scattering angle, there is an increasing intensity of scattering at 0° as the sector angle narrows. For very small values of the sector angle, the scattering becomes similar to that of a rod, with the exception that a scattering maximum is still seen at an angle close to that at which the spherulite scattering maximum occurs. The predictions of the model compare favorably with the scattering patterns observed for polymers in early stages of spherulitic growth.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1970.160081208
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  • 17
    Electronic Resource
    Electronic Resource
    Scattering of light by deformed disordered spherulites (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 517-529 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The change in the light-scattering patterns upon deforming two-dimensional disordered spherulites is shown to arise from four effects occurring upon stretching: (1) the change in shape of the spherulite, (2) the change in average orientation of the optic axes of the scattering volume elements, (3) the change in deviation of the optic axis orientation angle from its average value, and (4) the change in the distance over which this deviation is correlated. The effects of these contributions upon the experimental scattering patterns are analyzed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160090310
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  • 18
    Electronic Resource
    Electronic Resource
    Scattering of light by disordered spherulites. II. Effect of disorder in the magnitude of the anisotropy (1971)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 9 (1971), S. 1747-1761 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The contribution to the disorder scattering by imperfect spherulites resulting from fluctuations in the magnitude of the anisotropy is analyzed for two-dimensional spherulites. The fluctuations are described in terms of a parameter characterizing the meansquare amplitude of the fluctuation and a correlation function describing the distance over which the correlation occurs. Cases considered are those where the correlation depends on either the radial or the angular separation of the scattering volume elements. As with the case of disorder in orientation, one finds that disorder in anisotropy may result in a nonzero value of intensity at μ = 0° and 90°, a decrease in the higher-order variation of scattered intensity with θ, and an increase in the intensity of scattering at higher values of θ over that for a perfect spherulite. In addition, disorder in the angular direction leads to an increase in the scattered intensity at small values of θ as compared with the zero intensity of scattering from a perfect spherulite at θ = 0°.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1971.160091002
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  • 19
    Electronic Resource
    Electronic Resource
    X-ray diffraction relaxation of polyethylene (1972)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 10 (1972), S. 685-691 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The change in x-ray diffraction intensity with time following rapid stretching by various amounts is measured for a low-density polyethylene sample at several temperatures. An appreciable decrease in intensity with time at the meridian of the diffraction from the 110 and 200 planes is observed to occur within the first 5 sec following stretching. The change takes considerably longer times at lower temperatures. By use of a calibration curve, the change in crystal orientation functions for the a, b, and c crystal axes were calculated, and an increase in c-axis orientation was shown. From the results of birerringence measurements on the same sample, the crystalline and amorphous contributions to birefringence were calculated. It was shown that stretching is initially accompanied by a greater amount of amorphous than crystalline orientation, and that relaxation involves an increase in crystalline orientation accompanied by a decrease in amorphous orientation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1972.160100410
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  • 20
    Electronic Resource
    Electronic Resource
    Isotactic polypropylene foams crystallized from compressed propane solutions (1998)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 36 (1998), S. 617-627 
    Details
    ISSN: 0887-6266
    Keywords: isotactic polypropylene foams ; supercritical propane solutions ; high surface areas ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Crystallization of isotactic polypropylene (iPP) from homogeneous solution in supercritical propane yields open-cell foams of high surface area (120-150 m2/g). Their morphology usually consists of microspheres with a dense core and a porous periphery of radiating fibrils. Pore radii covering the mesopore range (2-50 nm), making their largest contribution at 10-20 nm, were calculated from nitrogen adsorption isotherms. Surface areas of the correct order of magnitude are obtained by assuming that gas adsorption takes place on the surfaces of lamellar crystals. Crystallization of iPP from n-butane and n-heptane generates foams of lower mesoporosity and smaller surface area. These more “liquid-like” solvents do not allow the formation of an open network of mesopores or they promote its collapse upon their removal. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 617-627, 1998
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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