Adhesive formulations for forming a fluorinated poly(imide-phthalonitrile) thermoset polymer are provided. Such an adhesive formulation may comprise a fluorinated imide-phthalonitrile oligomer having Formula IV ##STR00001##
wherein R.sub.1 is an unsubstituted or substituted aryl group and does not comprise an ether group; R.sub.2 is an unsubstituted or substituted aryl group and does not comprise an ether group; at least one of R.sub.1 and R.sub.2 comprises a fluorine substituent; and n has a value of from 1 to 30.

Described herein are shelf-stable adhesive compositions as well as methods of using thereof.

Described herein are shelf-stable adhesive compositions as well as methods of using thereof.

Disclosed herein are ionomer blends and high temperature polymer electrolyte membranes for use in electrochemical cells. The ionomer blends include a mixture of polyphosphonic acids and polysulfonic acids. The high temperature polymer electrolyte membranes include crosslinked polymeric networks.