Conductivity and dielectric behaviour studies of starch/PEO+xwt-%NH4NO3polymer electrolyte

Polymer blending is used to overcome the disadvantage of pure starch film, and in the present study, starch has been blended with poly(ethylene oxide) (PEO). The X-ray diffraction study shows that starch/PEO with a ratio of 7∶3 exhibits the least amount of crystallinity, and this was chosen in the preparation of polymer electrolyte. Films of starch/PEO blends were then prepared via solution casting technique, and their properties with different amounts of ammonium nitrate NH4NO3 were compared. The highest conductivity at room temperature of ∼2·81±0·46×107 S cm−1 was achieved with the addition of 35 wt-%NH4NO3. Dielectric data were analysed using complex permittivity and complex electrical modulus for the sample with the highest ionic conductivity. The relaxation time τ for these samples was determined, and the plot shows that τ decreases with conductivity of the complexes. The presence of peaks in the imaginary plots shows that the starch/PEO electrolyte system is an ionic conductor.