HIGHLY CONDUCTING LITHIUM POLYELECTROLYTES BASED ON MALEIC-ANHYDRIDE STYRENE COPOLYMERS

Comblike polyelectrolytes comprising immobilized carboxylic anions and poly(oxyethylene) (OCH2CH2)(n) side chains of various length were obt ained from the reaction of appropriate lithium alcoholates with maleic anhydride-styrene alternating copolymers. These materials may be fabr icated as films of ambient temperature conductivity in the range of 10 (-9)-10(-6) S.cm(-1), depending on the side-chain length. The conducti vity values increase by 2-3 orders of magnitude after the addition of strong polar plasticizers such as dimethyl sulfoxide and propylene car bonate. A further increase in conductivity was observed after the comp lexation of carboxylic anions by BF3. On the basis of C-13 NMR studies and Li-7 NMR relaxation times of lithium carboxylates, it was found t hat the anion complexing agent reduces ion pairing in polyelectrolytes more effectively than cation-solvating solvents. The possible conduct ion mechanism in the solid and gel polyelectrolytes is discussed.