Authors: Nasser Benrekaa
Addresses: Materials Physics Laboratory LPM, Faculty of Physics, University of Sciences and Technologies, USTHB, BP, 32 El-Alia 16111, Algiers, Algeria
Abstract: In this work the complex dielectric permittivity was measured from 10−1 to 1 MHz by dielectric dynamic spectroscopy (DDS). Thermally stimulated depolarisation current (TSDC) technique is used to investigate molecular mobility of cellulose. At high temperature, the various dielectric relaxation phenomena are separated by applying a recent analytical protocol. The comparison between the activation enthalpy values obtained by both techniques allows assignment of the α-mode to cooperative movements of nanometric sequences of the main chain. The strong/fragile model is used to explain the Arrhenius behaviour of this mode. The influence of water content on secondary and primary relaxation modes was examined.
Keywords: dielectric relaxation kinetics; thermally stimulated depolarisation current; TSDC; dielectric dynamic spectroscopy; DDS; cellulose; temperature; dielectric permittivity; water content; activation enthalpy.
International Journal of Materials Engineering Innovation, 2014 Vol.5 No.4, pp.307 - 315
Received: 26 Sep 2013
Accepted: 06 Jan 2014
Published online: 26 Feb 2015 *