Conductivities of solid polymer electrolyte complexes of alkali salts with polymers of methoxypolyethyleneglycol methacrylates

Abstract

The ac conductivities of solid polyelectrolyte complexes of alkali salts (NaSCN, NaCF 3SO 3, LiCF 3SO 3, LiCF 3SO 3) with polymers derived from methoxypolyethyleneglycol methacrylates of the general formula CH 2 = C(CH 3)COO(CH 2CH 2O) n CH 3 ( n = 8, 22) were measured as a function of temperature and salt content. The salts from crystalline or amorphous complexes with the polymers, some with a CH 2CH 2O to cation ratio as low as unity. The results were compared with the thermal characteristics of the complexes obtained from differential scanning calorimeter measurements. Crystallinity is reduced and conductance enhanced by lowering the salt content, adding an external plasticizer like propylene carbonate or by incorporating a comonomer like styrene into the polymer. The Arrhenius conductance plots are linear, and the conductivities with those reported for alkali salt complexes with poly (ethylene oxide).