Solid state properties of poly-β-hydroxybutyrate and of its oligomers
作者:
R. H. Marchessault,
Suzanne Coulombe,
Hiromichi Morikawa,
Keizo Okamura,
J. F. Revol,
期刊:
Canadian Journal of Chemistry
(NRC Available online 1981)
卷期:
Volume 59,
issue 1
页码: 38-44
ISSN:0008-4042
年代: 1981
DOI:10.1139/v81-007
出版商: NRC Research Press
数据来源: NRC
摘要:
The solid state properties of poly-β-hydroxybutyrate (PHB) were investigated for samples with degrees of polymerizationfrom 4 to 994. The observed melting points ranged from 47 °C to 180 °C. Electron diffractograms on carefully prepared single crystals of a high molecular weight sample provided data which confirmed the reportedaandbparameters from X-ray fiber diffraction and provided clear justification for theP212121space group. The observed intensities in the electron diffractogram, corresponding to (hk0) reflections, were compared with the predicted intensities for two proposed structures in the literature. The observed and calculated structure factors for both structures were in good agreement. Small angle X-ray diffraction of the meridional maximum for annealed "cold drawn" and "hot drawn" fibers showed a distinctly different dependence on temperature than the maximum for stacks of lamellar single crystals. For oligomers a long spacing was observed which was about twice the length of the samplemultiplied by the crystalline advance per monomer.
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