Plasticization of cross-linked polymer electrolytes

The plasticization of cross-linked poly(ethylene oxide)/poly(propylene oxide) copolymer electrolytes was investigated using low mol. wt. poly(ethylene oxide) PEO as plasticizer. These plasticizers were grafted on to the polymer networks (internal plasticization) or free (external plasticization). The conductivities of the plasticized polymer networks were measured at room temperature using LiClO4 as salt. Plasticization increased the conductivity and the gain depended on the plasticization-type, on the size of the plasticizer connected to the size of the copolymer and on the nature of the plasticizer. The glass-transition temperatures of the polymers were also measured and they varied in an opposite way versus conductivity.