The thermal expansion of mannan I obtained from ivory nuts

We have investigated the thermal expansion of mannan I crystals obtained from the endosperm of ivory nuts using X-ray diffraction in the temperature range of from room temperature to 250 °C on heating. Seven major diffractions were observed, and all the d-spacings gradually increased with increasing...

Full description

Saved in:
Bibliographic Details
Published in:Carbohydrate polymers 2007-10, Vol.70 (3), p.298-303
Main Authors: Hori, Ritsuko, Sugiyama, Junji, Wada, Masahisa
Format: Article
Language:English
Subjects:
Applied sciences
crystal structure
endosperm
Exact sciences and technology
Ivory nut
Mannan
mannans
Natural polymers
Physicochemistry of polymers
Phytelephas
seeds
Starch and polysaccharides
tagua nuts
Thermal expansion
vegetable ivory
X-ray diffraction
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:We have investigated the thermal expansion of mannan I crystals obtained from the endosperm of ivory nuts using X-ray diffraction in the temperature range of from room temperature to 250 °C on heating. Seven major diffractions were observed, and all the d-spacings gradually increased with increasing temperature. However, discontinuities indicating a phase transition were observed at a temperature of 130 °C. The unit cell parameters showed an anisotropic thermal expansion between the intermolecular hydrogen bonded direction and the covalently bonded direction, where the a and b axes lengths increased, but the c-axis length decreased with increasing temperature. Although the reason for the contraction of the c-axis length on heating is not clear, the thermal behavior should be related to the crystal structure and hydrogen bonding system of mannan I.
ISSN:0144-8617
1879-1344
DOI:10.1016/j.carbpol.2007.04.011