SINGLE-ION CONDUCTION IN UV-CROSS-LINKED FILMS OF POLY(URETHANE-CO-(ALKALI-METAL METHACRYLATES))

A series of crosslinked copolymers of poly(ethylene glycol-co-2,4-toly l diisocyanate-co-(alkali-metal methacrylates)) were prepared by copol ymerization of polyurethane oligomer with alkali-metal methacrylate. C ast films of these copolymers obtained by UV-crosslinked polymerizatio n are completely amorphous and have a relatively low T-g. The films pr ovide good mechanical properties and high ionic conductivity without a dditional solvent or inorganic salts. DC ionic conductivity of the fil ms at room temperature is stable over time indicating that the copolym er is a cationic single-ion conductor. AC conductivity of these films depends mainly on the ionic radius, segmental motion of the polymer ch ains and local environment of the ions in the polymer matrix.