Three Methods for In Situ Cross-Linking of Polyvinyl Alcohol Films for Application as Ion-Conducting Membranes in Potassium Hydroxide Electrolyte

摘要

Three methods of in situ cross-linking polyvinyl alcohol films are presented. They are: (1) acetalization with a dialdehyde such as glutaraldehyde, (2) acetalization with aldehyde groups formed by selective oxidative cleaving of the few percent of 1, 2 diol units present in polyvinyl alcohol, and (3) cross-linking by hydrogen abstraction by reaction with hydro¬gen atoms and hydroxyl radicals from irradiated water. For the third method, improve¬ment in film conductivity in KOH solution at the expense of mechanical strength is obtained by the presence of polyacrylic acid in the polyvinyl alcohol films. Resistivities in 45 per-cent KOH are given for in situ cross-linked films prepared by each of the three methods.