Jump to main content
Jump to site search
Access to RSC content Close the message box

Continue to access RSC content when you are not at your institution. Follow our step-by-step guide.


Issue 2, 1997
Previous Article Next Article

13C NMR spin–lattice relaxation times as a probe of local polymer dynamics in plasticized polyethers

Abstract

13 C NMR spin–lattice relaxation times T 1 are used to investigate the effect of low molecular weight diluents, including N,N-dimethylformamide, N-methylformamide, propylene carbonate, γ-butyrolactone, triglyme and tetraglyme, on the local polymer segmental motion in polyether–urethane networks. In all cases, an increase in the local mobility is deduced from the increasing T 1 measurements consistent with a decreasing glass transition temperature. The extent of plasticization, however, is dependent on the nature of the small molecules. Those molecules which can either form strong polymer-diluent interactions (for example through dipolar interactions) or are themselves rigid, give the least enhancement of polymer mobility and the greatest deviation from the Fox equation for T g . In the presence of alkali metal salts, N,N-dimethylformamide and propylene carbonate are shown to have opposite effects on the local polymer motion, as seen from the T 1 measurements. In both cases, addition of the plasticizers increases the 13 C T 1 relaxation times for the plasticizer. However, propylene carbonate decreases the polymer 13 C T 1 whilst N,N-dimethylformamide results in the expected increase in polymer 13 C T 1 .

Back to tab navigation

Article information


J. Mater. Chem., 1997,7, 193-201
Article type
Paper

13 C NMR spin–lattice relaxation times as a probe of local polymer dynamics in plasticized polyethers

M. Forsyth, P. Meakin and D. R. MacFarlane, J. Mater. Chem., 1997, 7, 193
DOI: 10.1039/A604781E

Search articles by author

Spotlight

Advertisements