Thermal depolarization currents of regenerated cellulose films

The thermal depolarization current technique is applied to plasticized and unplasticized regenerated cellulose films. In unplasticized cellulose, two depolarization current bands are observed. The band with a current maximum occurring near 298°K ( T m ), and with an activation energy, U , of 0.57 eV, is believed to be related to the second‐order transition which is known to occur in dry cellulose in the vicinity of 298°K. The second band, with T m = 215°K and U = 0.26 eV, is also present in the plasticized material, and possibly arises from primary hydroxyl group orientations. In cellulose films plasticized with glycerol, an intense band occurs at 271°K, with U = 0.51 eV, and is attributed to the plasticizer. A third band, occurring in the plasticized material near 300°K, has not been fully investigated.