Thermally resistant polymers for fuel tank sealants

Imide-linked perfluoroalkylene ether polymers, that were developed for the high temperature fuel tank sealant application, are discussed. Modifications of polymer structure and properties were realized through use of a new aromatic dianhydride intermediate containing an ether-linked perfluoroalkylene segment. Tests of thermal, oxidative and hydrolytic stability, fuel resistance, and adhesion are discussed along with tensile strength and elongation results. Efforts to effect a low temperature condensation of amic acid prepolymer to form imide links inside are described.