Sri Veiikateswnra Univcrsity,
Thermal depolarization currents of regenerated cellulose films
โ Scribed by Gary A. Baum
- Publisher
- John Wiley and Sons
- Year
- 1973
- Tongue
- English
- Weight
- 541 KB
- Volume
- 17
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
โฆ Synopsis
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,,,), and with an activation energy, U, of 0.57 eV, is believed to be related to the secondorder transition which is known to occur in dry cellulose in the vicinity of 298ยฐK. The second band, with T, = 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.
๐ SIMILAR VOLUMES
## Abstract Thermally stimulated discharge current measurements were made with cellulose acetate films at different polarizing fields and temperatures. While two peaks were obtained, in general, for specimens polarized at low fields and temperatures, only one peak was observed for higher fields and
## Synopsis Congo red bound to regenerated cellulose in highly swollen gel films formed by slow precipitation from LiCl/N,N-dimethylacetamide solution exhibits induced optical activity. The induced CD band of the dye vanishes when these films are dried under uniaxial stress, indicating that the ef