Evidence of inter-action between anion and polyether in the bulk

Poly(ethylene oxide) (PEO) derivatives having a positively-charged group on the chain end were prepared to analyze anion conduction mechanism in the p olyether moiety. Effects of the terminal group structure and anion species on the anionic conductivity were analyzed. The anionic conductivity of PEO- onium salts was about 10(-4) S cm(-1) at room temperature, which was much h igher than that for corresponding cation conductors. This difference should be based on much weaker interaction force of ether oxygens toward anions t han that for cations. The ionic conductivity was evaluated under the same s egmental motion by normalizing the different glass transition temperature ( T-g). As a result, reduced ionic conductivity was nearly equal among all ki nds of anion and cation conductive PEO oligomers having charged group on th e chain end. The T-g was revealed to mainly govern the ionic conductivity o f the matrix. Since the interaction between anion and ether oxygen was cert ainly detected but it was weak to suppress the elevation of T-g, lower T-g and corresponding high ionic conductivity were observed in these anion cond uctive polyethers. (C) 2000 Elsevier Science Ltd. All rights reserved.