Ionic conductivity polymer electrolyte film based on epoxidized deproteinized natural rubber (EDPNR) and lithium salt lithium triflate (LiCF3SO3) were prepared by solution casting technique. The EDPNR was prepared from deproteinized natural rubber latex (DNR) epoxidized in the latex stage with fresh peracetic acid 33%, which was deproteinized by incubation of the latex with 0,1 wt% urea and 1 wt% surfactant. The ionic conductivity of EDPNR mixed with lithium salt was investigated through impedance analysis. The results show that the conductivity of EDPNR/ LiCF3SO3 mixture was dependent on LiCF3SO3 salt concentration and amount of epoxy group. The highest ionic conductivity at room temperature obtained is 1,71 x 10-5 S.cm-1 at 35 wt% LiCF3SO3 and 45 mol% epoxy groups. Fourier transform infrared spectroscopy (FTIR) spectra showed evidence of complexation between EDPNR and LiCF3SO3. Glass transition temperature, Tg displayed an increasing trend in which are the increase in salt concentration and the increase in epoxy group concentration.
