Ionic conduction in poly(N,N-dimethylacrylamide) gels complexing lithium salts

Ionic conductivities of gel electrolytes prepared from poly(N,N,-dimethylacrylamide) (PDMA) and lithium salts (perchlorate and trifluoromethanesulphonate), incorporating N,N-dimethylacetamide (DMAc) as plasticizer, were studied. The molar mass of the polymer was controlled by use of ethane thiol as a chain transfer agent. The salt-free and salt-containing materials free from added DMAc were tough, non-crystalline, transparent solids. Complexes of high molar mass PDMA and lithium salts, incorporating 60% by weight of DMAc were tacky resins exhibiting bulk ionic conductivities from 2 × 10−4 S cm−1 at room temperature to 7 × 10−3 S cm−1 at 393 K. Rubbery solids were obtained by crosslinking the highly plasticized gels, and these materials had bulk ionic conductivities above 10−3 S cm−1 at room temperature.