HYDROGEN EXCHANGE BETWEEN CELLULOSE AND WATER: II. INTERCONVERSION OF ACCESSIBLE AND INACCESSIBLE REGIONS

Abstract

Exchange of hydrogen between water and some of the inaccessible hydroxyl groups in cellulose resulted from changes in the relative humidity and was most pronounced near 0 and 100% RH. A similar exchange occurred during prolonged immersion in liquid water. The extent of the reaction varied in different samples, increased with temperature, and was reproducible. By repeatedly wetting and drying cellophane, the exchange was cumulative and all the hydroxyl groups became exchanged after up to 100 cycles. The accessibility decreased slightly after repeated drying. The measurements were made by exchange with deuterated and tritiated water.The behavior was interpreted as an interchange of ordered and disordered regions resulting from molecular rearrangement caused by interaction between cellulose and water.