ION-CONDUCTING POLYMERS BASED ON MODIFIED ALTERNATING MALEIC-ANHYDRIDE COPOLYMER WITH OLIGO(OXYETHYLENE) SIDE-CHAINS

Comb-like polymers (CPs) based on modified alternating methyl vinyl et her/maleic anhydride copolymer with oligo(oxyethylene) side chains of the type -O(CH2CH2O)(n)CH3 were synthesized and characterized, and com plexed with lithium salts to form amorphous polymer electrolytes. Maxi mum conductivity close to 1.38 x 10(-4) S/cm was achieved at room temp erature and at a [Li]/[EO] ratio (EO = ethylene oxide) of about 0.066. The temperature dependence of ionic conductivity suggested that the i on transport was controlled by segmental motion of the polymer, shown by linear curves obtained in Vogel-Tammann-Fulcher plots. The ionic co nductivity maximum moved to a higher salt concentration as the tempera ture increased, indicating that a larger number of charge carriers can be transferred through polymer chains, of which free volume is increa sed at higher temperature. IR results indicated that the ester in CPs might decompose at 140 degrees C and reproduce the maleic anhydride ri ng.