Piezoelectricity in polyacrylonitrile

Abstract

The piezoelectric and related properties in ion-doped (NH4NO3, NaNO3) and undoped films of polyacrylonitrile have been measured as a function of temperature. The piezoelectric constants of both ion-doped and undoped films reach a maximum around 80°C and thereafter decrease markedly with temperature. At about this same temperature, a maximum of thermally stimulated discharge current (TSDC) is also observed with both ion-doped and undoped films. These two effects are thought to have a common origin: The randomization of nitrile dipoles in ordered regions. The piezoelectric constant of pre-stretched films is higher than that for unstretched polyacrylonitrile. © 1984 The Society of Polymer Science, Japan.