CHARACTERIZATION OF POLY(ETHYLENE OXIDE) SULFONIC-ACIDS

PEO sulfonic acids with [M(W)] in the range 446-4246 have been prepare d. Mechanically stable polyelectrolyte films containing high molar mas s PEO and PEO sulfonic acids were prepared. The PEO sulfonic acids and the polyelectrolyte films were examined by thermal analysis, optical microscopy, Raman spectroscopy, and impedance spectroscopy. While the low molar mass PEO sulfonic acids were completely amorphous, sulfonic acids with [M(W)] greater than or equal to 1246 show considerable crys tallinity. Experimental data indicate aggregation of the low molar mas s PEO sulfonic acids through hydrogen bonds. The PEO sulfonic acids ar e miscible with high molar mass PEO and form free standing polyelectro lyte films. The PEO sulfonic acids with the lowest molar masses have a plasticizing effect on the high molar mass PEG. The crystallinity of the films decreased as the concentration of sulfonic acid increased. T he films are stable at RH less than or equal to 75%, and for some mixt ures protonic conductivities of 10(-3) S cm(-1) at room temperature we re reached.