TY - GEN
T1 - Electrical and dielectric properties of new polyurethane ionomers
AU - Polizos, G.
AU - Kyritsis, A.
AU - Pissis, P.
AU - Shilov, V. V.
AU - Shevchenko, V. V.
PY - 1999
Y1 - 1999
N2 - Ionomers are polymers which contain charge groups in their molecular structure. Here we report the electrical and dielectric properties of new polyurethane ionomers based on poly(ethylene oxide) with nonionic hard segments of varying length and flexible segments containing alkali ions (Li+, Na+, K+) or protons (H+) by means of TSDC-DRS. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) were employed for structural investigation. The combined results by the different techniques indicate the coexistence of two morphologies: the microphase-separated structure characteristic of polyurethanes (hard-segment-rich microdomains in a soft-segment-rich matrix) and ionic aggregates (multiplets and clusters). Crystallization is observed at low hard segment contents (melting at about 305 K), the tendency for crystallization increasing upon hard segment extension and decreasing upon neutralization. Values of ionic conductivity are in the range of 10-4 S/m at 323 K, the conductivity in the amorphous polyurethanes being governed by the motion of the polymeric chains.
AB - Ionomers are polymers which contain charge groups in their molecular structure. Here we report the electrical and dielectric properties of new polyurethane ionomers based on poly(ethylene oxide) with nonionic hard segments of varying length and flexible segments containing alkali ions (Li+, Na+, K+) or protons (H+) by means of TSDC-DRS. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) were employed for structural investigation. The combined results by the different techniques indicate the coexistence of two morphologies: the microphase-separated structure characteristic of polyurethanes (hard-segment-rich microdomains in a soft-segment-rich matrix) and ionic aggregates (multiplets and clusters). Crystallization is observed at low hard segment contents (melting at about 305 K), the tendency for crystallization increasing upon hard segment extension and decreasing upon neutralization. Values of ionic conductivity are in the range of 10-4 S/m at 323 K, the conductivity in the amorphous polyurethanes being governed by the motion of the polymeric chains.
UR - http://www.scopus.com/inward/record.url?scp=0033313067&partnerID=8YFLogxK
M3 - Conference contribution
AN - SCOPUS:0033313067
SN - 0780350251
T3 - Proceedings - International Symposium on Electrets
SP - 321
EP - 324
BT - Proceedings - International Symposium on Electrets
PB - IEEE
T2 - 10th International Symposium on Electrets (ISE 10)
Y2 - 22 September 1999 through 24 September 1999
ER -