Novel fluorine-containing poly(aryl ether amide)s derived from 2,3,4,5,6-pentafluorobenzoic acid

Abstract

Various amide-containing aryl fluorides were synthesized from 2,3,4,5,6-pentafluorobenzoic acid, and novel fifteen AA-BB type and three AB type fluorine-containing poly(aryl ether amide)s (F-PEA) were obtained by nucleophilic aromatic substitution reaction. The synthesized aryl fluorides possessed several reactive carbons for the nucleophilic attack and cross-linking reaction occurred at 100°C. Polymerizations were carried out at 80°C to avoid cross-linking and stopped just before gelation occurred. They had all para connected linear structures. The obtained F-PEAs showed excellent solubility and afforded tough transparent films by casting method. They also exhibited high Tg in the range of 179-273°C depending on the molecular structure. They showed good thermal stability, and even though F-PEAs contained amide linkage into the repeating unit of polymer molecule, they exhibited excellent hydrophobicity due to the incorporation of 2,3,5,6-tetrafluoro-1,4-phenylene moiety.