Inventors:
Warren H. Philipp - North Olmsted OH
Charles E. May - Rocky River OH
Li-Chen Hsu - Westlake OH
Dean W. Sheibley - Sandusky OH
Assignee:
The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC
International Classification:
B05D 306
Abstract:
A self-supporting sheet structure comprising a water soluble, non-cross-linked polymer such as polyvinyl alcohol which is capable of being cross-linked by reaction with hydrogen atom radicals and hydroxyl molecule radicals is contacted with an aqueous solution having a pH of less than 8 and containing a dissolved salt in an amount sufficient to prevent substantial dissolution of the non-cross-linked polymer in the aqueous solution. The aqueous solution is then irradiated with ionizing radiation to form hydrogen atom radicals and hydroxyl molecule radicals and the irradiation is continued for a time sufficient to effect cross-linking of the water soluble polymer to produce a water-insoluble polymer sheet structure. The method has particular application in the production of battery separators and electrode envelopes for alkaline batteries. Low electrical resistivity, desirable in those applications, can be achieved by incorporating a highly conductive water soluble resin, such as polyacrylic acid, with the polyvinyl alcohol.