ISSN:
1435-1536
Keywords:
Key words Dielectric relaxation
;
water sorption
;
natural polymers
;
chitosan
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The dielectric properties of chitosan films with a degree of deacetylation of 86% have been investigated in the frequency range of 103–106 Hz covering a broad range of temperatures from −150 to 150 °C. The variation of the dielectric pro-perties with temperature has been associated with two dielectric processes: (a) a local relaxation attributed to the presence of hydrogen-bonded water appearing at low temperatures (b) a conduction process related to water molecules which becomes desorbed upon heating at T〉80 °C. Isothermal dielectric experiments have been performed in order to follow, in real time, the occurrence of both, the water sorption and desorption processes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s003960050099
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