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Title: Study of correlations between microstructure and conductivity in a thermoplastic polyurethane electrolyte

Abstract

Micro-Raman and positron annihilation lifetime spectroscopy (PALS) have been used to investigate the structure of a thermoplastic polyurethane/LiClO{sub 4} solid flexible polymer electrolyte at room temperature. Correlation between the free volume and carrier concentration with ionic conductivity was observed. The polyurethane soft phase consisted of a poly(tetramethylene glycol-co-ethylene glycol) copolymer reinforced by condensation with hexamethyldiisocianate. The range of salt concentration between 5 and 35 wt %, which attained the beginning of phase segregation, was also studied by differential scanning calorimetry (DSC), which showed the presence of three thermal events; the soft-phase T{sub g}, a change in heat capacity suggested as the hard-phase T{sub g}, and a hard-phase ordering endotherm. The total ionic conductivity was found to be approximately 4 {times} 10{sup {minus}6} S cm{sup {minus}1} at 23 C up to 27 wt % salt, whereas there were pronounced changes observed by the spectroscopic techniques. The PALS measurements indicated a decrease of 40% of the ratio (V{sub f}I{sub 3}/(V{sub f}I{sub 3}){sub 0}) between the free volume parameters probed by the positron particle. This ratio is proportional to the fractional free volume of the system. The micro-Raman results showed an increase of ionic aggregation, although the charge carrier concentration increased significantly inmore » the range of compositions studied. The opposite effects of the microstructural changes and the maximum conductivity value, in the observed range of concentrations, are discussed.« less

Authors:
 [1]; ; ; ;  [2]
  1. CDTN/CNEN, Belo Horizonte, MG (Brazil). Centro de Desenvolvimento da Tecnologia Nuclear
  2. UFMG/ICEx, Belo Horizonte, MG (Brazil)
Publication Date:
OSTI Identifier:
696644
Resource Type:
Journal Article
Journal Name:
Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical
Additional Journal Information:
Journal Volume: 103; Journal Issue: 34; Other Information: PBD: 26 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; POLYURETHANES; LITHIUM PERCHLORATES; POLYMERS; ELECTROLYTES; CRYSTAL STRUCTURE; IONIC CONDUCTIVITY

Citation Formats

Furtado, C.A., Silva, G.G., Machado, J.C., Pimenta, M.A., and Silva, R.A. Study of correlations between microstructure and conductivity in a thermoplastic polyurethane electrolyte. United States: N. p., 1999. Web. doi:10.1021/jp984601c.
Furtado, C.A., Silva, G.G., Machado, J.C., Pimenta, M.A., & Silva, R.A. Study of correlations between microstructure and conductivity in a thermoplastic polyurethane electrolyte. United States. doi:10.1021/jp984601c.
Furtado, C.A., Silva, G.G., Machado, J.C., Pimenta, M.A., and Silva, R.A. Thu . "Study of correlations between microstructure and conductivity in a thermoplastic polyurethane electrolyte". United States. doi:10.1021/jp984601c.
@article{osti_696644,
title = {Study of correlations between microstructure and conductivity in a thermoplastic polyurethane electrolyte},
author = {Furtado, C.A. and Silva, G.G. and Machado, J.C. and Pimenta, M.A. and Silva, R.A.},
abstractNote = {Micro-Raman and positron annihilation lifetime spectroscopy (PALS) have been used to investigate the structure of a thermoplastic polyurethane/LiClO{sub 4} solid flexible polymer electrolyte at room temperature. Correlation between the free volume and carrier concentration with ionic conductivity was observed. The polyurethane soft phase consisted of a poly(tetramethylene glycol-co-ethylene glycol) copolymer reinforced by condensation with hexamethyldiisocianate. The range of salt concentration between 5 and 35 wt %, which attained the beginning of phase segregation, was also studied by differential scanning calorimetry (DSC), which showed the presence of three thermal events; the soft-phase T{sub g}, a change in heat capacity suggested as the hard-phase T{sub g}, and a hard-phase ordering endotherm. The total ionic conductivity was found to be approximately 4 {times} 10{sup {minus}6} S cm{sup {minus}1} at 23 C up to 27 wt % salt, whereas there were pronounced changes observed by the spectroscopic techniques. The PALS measurements indicated a decrease of 40% of the ratio (V{sub f}I{sub 3}/(V{sub f}I{sub 3}){sub 0}) between the free volume parameters probed by the positron particle. This ratio is proportional to the fractional free volume of the system. The micro-Raman results showed an increase of ionic aggregation, although the charge carrier concentration increased significantly in the range of compositions studied. The opposite effects of the microstructural changes and the maximum conductivity value, in the observed range of concentrations, are discussed.},
doi = {10.1021/jp984601c},
journal = {Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical},
number = 34,
volume = 103,
place = {United States},
year = {1999},
month = {8}
}