• Korean Chemical Engineering Research
• /
• v.47 no.4
• /
• pp.476-480
• /
• 2009

A polymer composite electrolyte of a blend of poly(methyl methacrylate)(PMMA) and poly(ethylene oxide) (PEO) as a host polymer, the ethylene carbonate as a solvent, and $LiClO_4$ as a salt was studied. The crystallinity of the polymer electrolytes was evaluated using differential scanning calorimeter(DSC). The ionic conductivity of the polymer electrolytes was measured by frequency response analyzer(FRA) method. The effect of PEO/PMMA blend ratios on the ionic conduction in these electrolytes was investigated. The electrolyte films showed a phase separation due to immiscibility of the PMMA with the PEO. The PMMA-rich phase and the PEO-rich phase were produced during a film casting. The ionic conductivity of blend electrolyte was dependent on the content of PMMA and showed the highest value at 20 wt.%. However, when PMMA content exceeds 20 wt.%, the ionic conductivity was decreased due to the slow ionic transport through the PMMA-rich phase.

• Bulletin of the Korean Chemical Society
• /
• v.10 no.2
• /
• pp.123-128
• /
• 1989

Calorimetric study in conjunction with Fourier-transform infrared (FTIR) spectroscopic study was carried out on the blends of poly(ethylene oxide) (PEO) with isotactic, atactic and syndiotactic poly(methyl methacrylate) (i-, a-, and s-PMMA). From the differential scanning calorimetric (DSC) measurements, the three types of blends show a depression of the melting temperatures. This indicates that PEO is compatible with i-, a-, and s-PMMA. But the largest melting point depressions of PEO are always found in the blends with s-PMMA. For PEO/a-PMMA and PEO/s-PMMA, the degree of crystallinity as a function of composition deviates substantially from that of the ideal blend in which no interaction between the components exists. The FTIR spectra of all three types of blends are recorded. In order to observe the microstructural changes of PEO in blends, we analyzed the spectra using digital weighted subtraction and addition techniques. It was concluded that the microstructures of PEO are strongly perturbed by the PMMA's. Among these blends PEO microstructure in PEO/s-PMMA blends is most greatly influenced. It indicates that the blending is most preferred with s-PMMA than a- and i-PMMA. It can be explained on the basis of the molecular structure of PMMA's.

• Korean Chemical Engineering Research
• /
• v.49 no.6
• /
• pp.758-763
• /
• 2011

In this work, polymer composite electrolytes were prepared by a blend of poly(methyl methacrylate) (PMMA) and poly(ethylene oxide) (PEO) as a polymer matrix, propylene carbonate as a plasticizer, $LiClO_4$ as a salt, and by containing a different content of $TiO_2$, by using the solution casting method. The crystallinity and ionic conductivity of the polymer electrolytes was evaluated using X-ray diffraction(XRD) and AC impedance method, respectively. The morphology of composite electrolyte film was analyzed by SEM method. From the experimental results, by increasing the $TiO_2$ content, crystallinity of PEO was reduced, and ionic conductivity was increased. In particular, the ionic conductivity was dependent on the content of $TiO_2$ and showed the highest value 15 wt%. However, when $TiO_2$ content exceeds 15 wt%, the ionic conductivity was decreased. According to the surface morphology, the ionic conductivity was decreased because the polymer composite electrolytes showed a heterogenous morphology of fillers due to immiscibility or aggregation of the filler within the polymer matrix.