Far-Infrared Study of Hydrogen Bonding in a Semicrystalline Polyurethane

Far-infrared spectroscopy was used to probe the hydrogen bond vibrational mode of a semicrystalline polyurethane. This vibration was assigned to a broad band appearing at 101 cm exp --1 in amorphous samples and 107 cm exp --1 in highly ordered samples. Using a rigid-body approximation, force constan...

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Bibliographic Details
Published in:Macromolecules 1989-06, Vol.22 (6), p.2564-2569
Main Authors: Shen, D Y, Pollack, S K, Hsu, S L
Format: Article
Language:English
Online Access:Get full text
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Summary:Far-infrared spectroscopy was used to probe the hydrogen bond vibrational mode of a semicrystalline polyurethane. This vibration was assigned to a broad band appearing at 101 cm exp --1 in amorphous samples and 107 cm exp --1 in highly ordered samples. Using a rigid-body approximation, force constants associated with the H bond stretching were calculated to be 0.52 and 0.58 mdyn/A for the two forms, respectively. In oriented samples, the band showed the appropriate perpendicular dichroism. The band showed sensitivity to both molecular order and temperature. A band located at 320 cm exp --1 was assigned to a O--C--NH--C bending mode coupled to the methylene chain bending. This band also showed sensitivity to chain conformation and packing and had high parallel dichroism in oriented samples. Spectra. 30 ref.--AA
ISSN:0024-9297
DOI:10.1021/ma00196a003