Co-solvent effect on conductivity of composite electrolytes comprising polyethylene oxide and polytetramethylene glycol-based waterborne polyurethanevia a mixture design approach

The co-solvent effect of the three solvents, ethlyene carbonate (EC), propy lene carbonate (PC), and diethylene carbonate (DEC) on the composite electr olytes (CE) consisting of polyethylene oxide (PEO) and polytetramethlyene g lycol-based waterborne polyurethane [WPU(PTMG)] was investigated by using a mixture design approach. The conductivity data at temperatures of 5, 25, 4 5 and 65 degreesC were fitted by employing a forward stepwise regression pr ocedure. Unfortunately, as a result of negligible conductivity of EC at T-m (similar to 40 degreesC), the test statistics gave values for R-adj(2) as 0.69 and 0.71 for the regression equations at 5 and 25 degreesC, respective ly. The regression equations at 45 and 65 degreesC were used to construct c ontour plots which facilitated the comparison of synergistic/antagonistic e ffects among the selected solvents. Molecular simulation was also made on t he basis of the radius distribution function. The results obtained are used to interpret the results through contour plots and also using the physical properties of the solvents. (C) 2000 Published by Elsevier Science B.V.