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  • Articles  (6)
  • Wiley-Blackwell  (6)
  • 1975-1979  (1)
  • 1955-1959  (5)
  • 1
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Es wurde ein Übergang 2. Ordnung von Cellulosetriacetat bei ca. 30°C mit Hilfe der Polarisations-Infrarot-Spektroskopie untersucht. Die Temperaturabhängigkeiten des IR Dichroismus der Banden bei 900 cm-1 (C1—H Biegeschwingung) und 600 cm-1 (Acetyl-Gruppenfrequenz) wurden untersucht. Die 900 cm-1 Bande zeigte einen Übergang bei ca. 30°C, während die 600 cm-1 Bande keine bemerkenswerte Änderung zeigte. Diese Ergebnisse legen nahe, daß der hier beobachtete Übergang wahrscheinlich einem Konformationswechsel des Pyranoserings zugeordnet werden kann. Es wird angenommen, daß der Übergangsmechanismus einer Sessel (C 1)-Wannen (B) Konformationsänderung des Pyranoserings bei der Faltung des Cellulosemoleküls zukommt.
    Notes: A second-order transition of cellulose triacetate at approximately 30°C was studied by polarized infrared spectroscopy. The temperature dependences of infrared dichroismus were examined for the 900cm-1 (C1—H bending vibration) and 600 cm -1 (acetyl group frequency) bands. The former changed at about 30°C, whereas the latter did not show any remarkable change. These results suggest that the transition observed here is probably related to the conformational change of the pyranose ring. The transition mechanism is supposed to be associated with the chair (C 1)-boat (B) transformation of the pyranose ring at the folding of the cellulose molecule.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 2 (1959), S. 66-70 
    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: Crystallization and orientation of isotactic polypropylene film by stretching were investigated. The specimen used was a film of thickness 0.03 mm. and had ca. 30% crystallinity in the initial state. It was observed both by x-ray examination and measurement of density that the crystallization of the stretched film increased proportionally to the stretching ratio. And it was confirmed that a quasi-crystalline structure was already developed in the low stretching ratio coexisting with the ordinary stable crystalline structures. This quasi-crystal structure can be easily transformed into the ordinary stable state at above 100°C., as well as the quasi-crystal structure in melt spinning filament, as described in a previous paper. It was also confirmed that the ordinary stable crystalline part was biaxially oriented by high stretching at room temperature, that is, (110) plane of the crystallite was preferentially oriented perpendicular to the surface plane of the film in the cross section perpendicular to the stretching axis. This phenomenon was elucidated from both the cohesive interactions between lattice planes and the compressive stress in the stretching process.
    Additional Material: 10 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 2 (1959), S. 62-65 
    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: A highly biaxially oriented isotactic polypropylene was obtained by stretching and rolling repeatedly. In such treatment, it was confirmed by x-ray examination that the 010 spacing was oriented parallel to the plane of rolling.
    Additional Material: 7 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 20 (1956), S. 567-577 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The ion exchange equilibrium constants were obtained by measurements of infrared spectra of the ion exchange resin phase, using carboxymethylcellulose film (degree of etherification 0.66) as ion exchanger. The apparent constants are calculated by the following equation: \documentclass{article}\pagestyle{empty}\begin{document}$${\rm p} K_a = r_{\rm B} \log {\rm \varepsilon }_{\rm A} \log k\varepsilon _{\rm B} - (r_{\rm B} - r_{\rm A} ){\rm }\log {\rm }(\varepsilon _{\rm A} + k\varepsilon _{\rm B} ) + r_{\rm A} \log B^{ + r_{\rm B} } - r_{\rm B} \log A^{ + r_{\rm A} } + \log {\rm }(\gamma _{\rm B}^{r_{\rm A} } /\gamma _{\rm A}^{r_{\rm B} } )$$\end{document} where A and B are the concentrations of the two exchangeable cations, respectively, rA is the valence of the A ion, γA is the activity coefficient of the A ion in the electrolyte solution, ∊A is absorption intensity of carbonyl band of the carboxy radical having the A ion in an exchanger, and k is a constant. The dependence of the apparent equilibrium constants on pH and the ionic concentration in the electrolyte was investigated in the Na-H, K-H, NH4-H, Ca-H, and Sr-H exchange systems. Further, the activity coefficients of the exchangeable ions in the resin phase were evaluated in both the uniunivalent and unidivalent exchange systems. It is concluded that the abnormal behavior of the coefficients in the resin phase would be explained by the interaction energy between the ion pairs in the resin phase, independent of the concentration of the electrolyte solutions, in the range of comparatively dilute electrolyte solutions.
    Additional Material: 5 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 39 (1959), S. 427-433 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Orientation of crystallites in stretched isotactic polypropylene filaments was examined by x-ray diffraction. It was found that complete overall orientation parallel to the direction of stretching is obtained at a stretching ratio of 4 to 5. Preferential orientation was observed in the stretching process, that is, the orientation of the 010 plane along the fiber axis was predominant in the initial step of orientation and was complete by 100% stretching. It was found that a new crystal structure was formed on further stretching of completely oriented filaments at or slightly above room temperature. The crystal structure can be transformed to an ordinary stable crystal structure by treating the filaments at 100 to 150°C. for comparatively short time. The crystal structure may be a kind of metastable crystal, with nearly hexagonal projection in the plane perpendicular to the fiber axis.
    Additional Material: 7 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 27 (1958), S. 596-597 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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