No abstract

To obtain thermally stable and mechanically strong sodium and lithium conducting polymers, we prepared Na+ and Li+ poly(phenylene terephthalamide sulfonate salts) (MW ∼ 5500). We also synthesized oligo(ethylene oxide) (3, 5, or 7 units of ethylene oxide) substituted ethylene carbonate and poly[oxymethylene‐oligo(oxyethylene)]. These are high boiling point liquids with high dielectric constants as well as metal chelating properties. Polyelectrolyte systems were prepared by mixing Na+ or Li+ poly(phenylene terephthalamide sulfonate) salts with various amounts of modified ethylene carbonate and/or poly[oxymethylene‐oligo(oxyethylene)]. Films (0.1–0.5 mm thick) obtained from the blends were found to have considerable mechanical strength; forming free standing films. The ionic conductivities of the Na+ and Li+ polyelectrolyte systems were 10−6−10−5 S/cm at 25°C. Thermal properties of these blend systems were investigated in detail. © 1994 John Wiley & Sons, Inc.

Ionic conductors based on N-substituted oligo(ethy1ene oxide) poly(p-phenylene terephthalarnide) (PPTA) were investigated. Two different PPTAs '(Mv = 12,000 and 3600) were grafted with tri(ethy1ene oxide) and hexa(ethy1ene oxide). These modified PPTAs were found to be soluble in organic solvents such as dimethyl acetamide and dimethyl sulfoxide and were miscible with various concentrations of oligo(ethy1ene oxide). The resulting blends formed complexes with lithium trifluoromethanesulfonate (LiS0,CFJ. The thermal and ionic conductive properties of the blends were investigated. The conductivities of some of the blends were in the range of 0.5-5.0 X S/cm at 25°C and 0.5-5.0 x Slcm at 100°C. The profile of conductivity at various temperatures followed the Vogel-Tammann-Fulcher (VTF) plots and it suggested that the major ionic transport took place in the amorphous phase.