Abstract:
Plasticized polymer electrolytes composed of chitosan as the host polymer, dimethyl
formamide (DMF) as the plasticizer and Glycolic acid (GA) as the doping salt were
prepared by the solution cast technique. These complexes with different amounts of
plasticizers were investigated as possible ionic conducting polymers. FTIR studies of the
chitosan acetate (CA), plasticizer dimethyl formamide (DMF) and their mixtures with
Glycolic acid were carried out. CA-GA-DMF spectra for various salt concentrations
showed shifting of the band at 767 cm-
1
to higher wavenumber at 798 cm-
1
•
The band at
1
767 cm-
represents the O=C---N group of DMF. The interaction is between the acid
cation and the oxygen atom of the O=C---N since the IR spectrum did not show any shift
in the C--N symmetric stretching band due to OH--N interaction. The splitting of the C
·-N symmetric stretching vibration of the plasticizer into a doublet at 865 and 880 cm-
is
evidence of plasticizer-polymer interaction. These shifted peaks were observed to
increase intensity with the increase of salt concentration. In the EIS analysis, the highest
ionic conductivity of solid thin film interaction at room temperature was observed to be
5.12x 10
1
-s
1
scm-
for sample with 30 wt. % concentrated DMF. The temperature
dependence conductivity shows that it followed the Arrhenius rule. The highest dielectric
constant ( Er
) and highest dielectric loss ( e;
) values were both appeared at the highest
temperature.
