Influence of water on the dielectric behaviour of chitosan films |
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| Authors: | A Nogales T A Ezquerra D R Rueda F Martinez J Retuert |
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| Institution: | (1) Instituto de Estructura de la Materia, C.S.I.C., Serrano 119 Madrid 28006, Spain, ES;(2) Departamento de Química Facultad de Ciencias Físicas y Matemáticas Universidad de Chile Casilla 2777, Santiago-Chile, CL |
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| 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.
Received: 20 June 1996 Accepted: 19 November 1996 |
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| Keywords: | Dielectric relaxation water sorption natural polymers chitosan |
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