Electrical Relaxation in Pure and Alkali Metal-Thiocyanate Complexed Poly(Ethylene Oxide).
Interim technical rept.,
CASE WESTERN RESERVE UNIV CLEVELAND OHIO DEPT OF PHYSICS
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Audio frequency complex admittance and DSC studies have been performed on pure polyethylene oxide PEO and PEO complexed with alkali metal thiocyanates over the temperature range 5.5-380K. The dielectric constant of the complexed materials is found to be greater than for pure PEO. A discontinuity in the conductivity is found which increases in temperature as the size of the cation increases. In every case, the discontinuity is associated with a feature in the DSC results. Next, some evidence is given that water may enhance the formation of amorphous complexed PEO. In pure PEO, alpha sub a and gamma relaxations are observed in good agreement with previous work. A thermal anomaly is found corresponding to alpha sub a . In addition, alpha sub c is identified in pure PEO. Very little difference is found for the gamma relaxation between pure PEO and PEO-LiSCN and PEO-NaSCN. For PEO-KSCN, three distinct peaks are found in the gamma relaxation region. These results are consistent with a tgt infinity tg-t transition interpretation for gamma where the cations reside within the helical channels at low temperatures. Author
- Organic Chemistry
- Electricity and Magnetism