Tailoring poly(ether-imide) films features towards high performance flexible substrates

Abstract

Abstract A series of films prepared from poly(ether-imide)s (PEI) containing a hydroxyl group and various flexible bridges has been investigated to survey the applicative potential. The structure-property correlations were studied to explore the influence of the structural design on the overall physico-chemical properties. FTIR spectra confirmed the complete imidization of polyamidic acid precursors used for films preparation. These films exhibited high glass transition temperatures, and two stages of decomposition, being thermally stable up to 400\xa0°C, with a char residue up to 68.97 %. A systematic non-isothermal kinetic study was accomplished to evaluate the kinetic parameters of the thermogravimetric curves. The dielectric behaviour of the PEI films was assessed on the bases of dielectric constant, dielectric loss, secondary relaxations, dielectric loss processing by Havriliak-Negami model and conductivity studies. Beside the mechanical behaviour evaluation, these polymer films were subjected to chemical resistance tests in the presence of methyl ethyl ketone and an alkaline solution. To prove their suitability for use as flexible electrodes, e.g. electrochemical storage devices, the films were coated with a graphite-containing paint and analysed in comparison with indium tin oxide-coated glass with respect to the electrical response in a standard electrochemical cell.