Dielectric study of dry and hydrated microcrystalline cellulose

Thermally stimulated depolarization current (TSDC) measurements on dry and hydrated compressed pellets of microcrystalline cellulose, in the temperature range of 77-300 K, show three main dielectric dispersion bands: (i) a complex band in the region of 80-200 K, attributed to the reorientation of polar groups of cellulose; (ii) a broad peak in the region of 128-145 K, attributed to the polarization of loosely bound sorbed water molecules, which for high water content dominate in this temperature region; and (iii) a broad dispersion peak appearing in the region of 180-260 K, attributed to the motion of polar groups of cellulose facilitated by sorbed water