A study of sorbed water on cellulose by the thermally stimulated depolarisation technique

The dielectric behaviour of compressed pellets of hydrated cellulose was studied by the thermally stimulated depolarisation (TSD) current technique in the temperature range of 77-300K in an attempt to determine the binding modes of water molecules. The water content was varied between 1.1 and 22.1%. Two broad dielectric dispersion bands were observed. The first dispersion band at lower temperatures is attributed to the reorientation of sorbed water molecules. A model is proposed which accounts for the different dielectric behaviour of water molecules in cellulose and in pure water. The second dispersion band at higher temperatures is complex. Its magnitude and position depend strongly on the water content.