Accession Number:

ADA175553

Title:

NMR, DSC, TMA, and High Pressure Electrical Conductivity Studies in Solid, Crosslinked Dimethylsiloxane-Ethylene Oxide Copolymer Networks Containing Sodium.

Descriptive Note:

Interim technical rept.,

Corporate Author:

HUNTER COLL NEW YORK DEPT OF PHYSICS AND ASTRONOMY

Report Date:

1986-12-30

Pagination or Media Count:

30.0

Abstract:

Audio frequency electrical conductivity and Sodium 23 NMR studies hae been carried out on solid, crosslinked dimethylsiloxane-ethylene oxide copolymer networks containing sodium. The measurements have been carried out in vacuum over the temperature range 5-380K and at pressures up to 0.65 GPa over the temperature range 230-380K. The electrical conductivity for the complexed material and the electrical relaxation time associated with the alpha relaxation in the uncomplexed material exhibit VTF or WLF behavior. From a VTF analysis of the electrical conductivity, E sub a is found to be about 0.11 eV and T sub o is found to be about 45 C below the central glass transition temperature as determined by both DSC and TMA. Also, T sub o is found to increase about 50 KIGPa and E sub a increases significantly with pressure. In addition, the high pressure studies show that the activation volume associated with the electrical conductivity decreases from 44 to 23 ccml over the temperature range 262-323K. The Sodium NMR measurements reveal the presence of both bound and mobile sodium species, the relative concentrations of which change by about a factor of 10 over the temperature range -100 to 100 C. Broadening of the bound Sodium line above room temperature suggests the possible presence of ion pairs or higher aggregates in the complex.

Subject Categories:

  • Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE