CTS - 9632079 Peter Pintauro Tulane University ABSTRACT The project involves the fabrication of crosslinked and sulfonated cation-exchange membranes from alkylphenoxy- and alkylphenoxy/phenoxy-substituted polyphospazenes. Phosphazene polymers are promising base-materials for new membranes due to their chemical and thermal stability and the ease of modifying the polymer by adding different side-chains onto the -P=N- Backbone. The chemical and mechanical properties of the resulting membranes will be characterized. The membranes will differ in chemical composition, ion-exchange capacity, and degree of crosslinking. Potential applications of the membranes include electrodialysis and ultrafiltration, as well as solid polymer electrolyte fuel cells.