New type polymer electrolyte films based on poly(acrylonitrile), (PAN), and cyanoethylated poly(vinyl alcohol), (CN-PVA), were prepared and their conducting behaviors were investigated. CN-PVA was prepared from poly(vinyl alcohol), (PVA) and acrylonitrile in the presence of sodium hydroxide and quaternary ammonium halide as a phase transfer catalyst. Free standing PAN- and CN-PVA-based electrolyte films were prepared by casting the propylene carbonate (PC) solution containing PAN, CN-PVA and LiClO4 and removing some amount of PC. Ionic conductivity of the electrolyte film, (PAN)10(CN-PVA) 10(LiClO4)8(PC)4 composite film was 14.6 mS cm(-1) at 30 degrees C and 22.4 mS cm(-1) at 60 degrees C. FTIR results for the electrolyte films suggest that the nitrile groups in the CN-PVA matrix mainly interact with the lithium ions in the films and enhance dissolution of the lithium salt in the electrolyte films. (c) 2006 Elsevier B.V. All rights reserved.