ABSORBED WATER IN THE CORK STRUCTURE - A STUDY BY THERMALLY STIMULATED CURRENTS, DIELECTRIC-RELAXATION SPECTROSCOPY, ISOTHERMAL DEPOLARIZATION EXPERIMENTS AND DIFFERENTIAL SCANNING CALORIMETRY
Msc. Dionisio et al., ABSORBED WATER IN THE CORK STRUCTURE - A STUDY BY THERMALLY STIMULATED CURRENTS, DIELECTRIC-RELAXATION SPECTROSCOPY, ISOTHERMAL DEPOLARIZATION EXPERIMENTS AND DIFFERENTIAL SCANNING CALORIMETRY, Journal of Materials Science, 30(17), 1995, pp. 4394-4400
This paper reports on a modification of the dielectric properties of c
ork which occurs as a consequence of heating above 60 degrees C or eva
cuation for several days. This phenomenon was observed using different
experimental techniques (thermally stimulated currents, dielectric re
laxation spectroscopy, isothermal depolarization experiments and diffe
rential scanning calorimetry), and the corresponding kinetics were ana
lysed. It was observed that the original properties of co rk were reco
vered if the sample was exposed to room air for several weeks. It is s
uggested that the reported modification of the dielectric properties a
rises from desorption, induced by heating or evacuation, of water mole
cules absorbed in the cork structure.