ISSN:
0098-1273
Keywords:
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Carbon-13 NMR spin-lattice relaxation times T1 of poly(N-vinyl pyrrolidone) (PVP) and PVP-iodine have been studied in several solvents and at different temperatures. Three kinds of motion can be identified from the T1 data: segmental motion, ring rotation, and ring puckering. The effective correlation time for segmental motion is calculated to be 1 × 10-9s, in good agreement with published proton NMR data. Another solvent, 1,1,2,2-tetrachloroethane, behaves like D2O, the segmental correlation time being 3 × 10-9s. In benzene, however, the linewidths are very broad and tend to narrow with increasing temperature, but the T1s are not very different from those of PVP in D2O. The results suggest association of pyrrolidone rings in benzene that reduces chain dimensions and also restricts chain mobility. As for PVP-iodine in water, again broad resonances are observed which sharpen considerably at higher temperatures. The result agrees with previous suggestions of specific interactions between the pyrrolidone group and iodine.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pol.1985.180230304
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