The effect of dmf plassticizer on chitosan-glycolic acid solid polymer electrolyte

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.