Processable Phthalonitrile Resins with High-Thermal and Oxidative Stability

A processable multiple aromatic ether-linked phthalonitrile with high thermal and oxidative stability has been synthesized and characterized. The oligomeric phthalonitrile monomer was prepared in a two-step, one-pot procedure using an excess amount of resorcinol and 4,4'-difluorobenzophenone in a N,Ndimethylformamide/toluene mixture and K2CO3 as the base followed by end-capping with 4-nitrophthalonitrile. The monomer was thermally crosslinked in the presence of bis(4-[4-aminophenoxy]phenyl)sulfone forming a void-free thermoset. Thermal, oxidative, and mechanical measurements were performed on the resulting polymer. The polymer exhibits excellent thermal and oxidative stability, superior mechanical properties, and low water absorption