Ionic conductivity in the poly(ethylene malonate)/lithium triflate system

A series of polymer salt complexes based on poly(ethylene malonate) and lithium triflate were prepared with polymer repeat unit to cation ratios of 8, 4, 2, 1. These were characterized and then mixed with lithium triflate. The CO stretching peaks in the IR spectra of these polymers became broad when salt was introduced, indicating complex formation between the polymer and the lithium cation. Pure poly(ethylene malonate) has a glass transition at 258 K and the glass transition temperature increases with increasing salt concentration. The maximum room temperature ionic conductivity for this polymer/salt complex is 1.6×10−6 S/cm for a polymer repeat unit to cation ratio of 8, and the temperature dependence of the conductivity follows the Vogel–Tammann–Fulcher (VTF) equation.