T. Kimura et al., HIGH-RESOLUTION SOLID-STATE C-13 NMR-STUDY OF ETHYLCELLULOSE FILMS, Journal of polymer science. Part B, Polymer physics, 31(6), 1993, pp. 671-676
Ethylcellulose films cast from concentrated solutions of chloroform, b
enzene, and carbon tetrachloride were subjected to the NMR relaxation
measurements including H-1 spin-lattice relaxation time (T1H), rotatin
g-frame H-1 spin-lattice relaxation time (T1rhoH), and C-13 spin-latti
ce relaxation time (T1C). The values of T1rhoH for carbons in the gluc
ose units of ethylcellulose were of the same order of magnitude as tho
se reported for the crystalline and noncrystalline regions of ramie ce
llulose. The values of T1C for unsubstituted C2, C3 carbons were small
er than those for the corresponding carbons in the noncrystalline regi
on of native celluloses. The T1C values for unsubstituted C2, C3, and
substituted C6 carbons showed a small but definite dependence on the s
olvent from which the films were cast.