Preparation, characterization, and ion conductivities of the polymer electrolytes based on poly(ethylene oxide)-g-poly(ethylene glycol)

Abstract

The comb-shaped polyethers, poly(ethylene oxide)-g-poIy(ethylene glycol)s, (PEO-g-PEGs) were prepared by condensation polymerization of poly(ethylene glycol) ((M) over bar(w) = 400) and 3-chloro-2-chloromethyl-1-propene (CCMP) followed by a graft reaction with poly(ethylene glycol) methylether, and their ionic conduction behavior was investigated. The ionic conductivities of the PEOg-PEG complexed with LiCF3SO3 were investigated by varing the side chain length of the graft polymers and also the salt concentration. The maximum ion conductivity obtained fi om the graft polymer-based polymer electrolytes was 4.0 x 10(-5) S cm(-1) at 25 degrees C. The shift of the optimum [EO]/[LiCF3SO3] for maximum ion conductivity to a higher value compared to pristine and conventional linear PEO was observed, and it seemed to be due to the enhanced salt solvation imparted by the graft structure of PEO-g-PEG. The crosslinking of PEOg-PEG by a free radical reaction could provide the improved mechanical property of the polymer electrolytes.