High-molar-mass branched poly[oxymethylene-oligo(oxyethylene)] for use in polymer electrolytes

Abstract

High-molar-mass poly[oxymethylene-oligo(oxyethylene)](POMOE, oxymethylene-linked PEG400) was prepared by inclusion of a multifunctional alcohol in the polycondensation recipe. Approximate values of the critical concentration for gelation were determined. Branching in samples prepared at lower-than-critical concentrations was confirmed by comparison of molar masses determined by gel-permeation chromatography and static light scattering. Melt flow indices confirmed an increase in viscosity. Differential scanning calorimetry and dynamic mechanical thermal analysis were used to determine glass-transition and melting temperatures of the polymers and of mixtures of the polymers with lithium perchlorate. Conductivities of polymer–salt mixtures were measured. Comparison of results for branched and linear polymers indicated no significant difference in properties, including conductivity, apart from a decrease in melt flow index.