Polyether/salt hybrid (IV). Effect of benzenesulfonate group(s) and PEO molecular weight on the bulk ionic conductivity

✍ Scribed by Kaori Ito; Yoichi Tominaga; Hiroyuki Ohno

• Book ID: 104115008
• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 985 KB
• Volume: 42
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/s0013-4686(96)00317-9

✦ Synopsis

Benzenesulfonate (Bs) groups were introduced to the terminal of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) oligomers with molecular weight (MW) of 30&6000 to design an ion conductive amorphous matrix. The phase of these PEO-salt hybrids was mainly influenced by the MW of the polyethers. PEO oligomers having benzenesulfonate group(s) with MW less than 600 showed amorphous phase in the bulk in a wide temperature range (-120 -+ 150°C). The ionic conductivity of these amorphous salts was considerably influenced by the glass transition temperature (r,). The Tg of these PEO-salt hybrids was influenced by the fraction of salt group in the matrix. Among totally amorphous salts, the best ionic conductivity of 2.95 x 10e5 S cm-', at 50°C was obtained in the PEOsso-BsCs. Though PE03so-BsM was also an amorphous salt, lower ionic conductivity was observed because of higher TB than that of PEO~X~-BSM. However, PEO~~O-BSM was useful as electrolyte in PEO oligomers because of excellent compatibility with the PEO oligomers. The ionic conductivity of PEOX~-BsM in PEO~W (MW of 300) was 40 times higher than that of PE0350-BsM in the bulk. Since PE0350-BsM was inherently ion conductive, the ionic conductivity for PE03so-BsM/PE0300 was kept high regardless of the salt concentration.