Synthesis and characterization of aromatic poly(ether ketone oxadiazole)s

A general method for the preparation of oxadiazole containing aromatic poly(ether ketone)s has been developed. Polymerization is based on a ketone-activated halo displacement in oxadiazole containing bis(4-fluorobenzoyl) moieties by phenoxides. 2,5-bis[4-(4-fluorobenzoyl-(4-phenoxyphenyl)]-1,3,4-oxadiazole was prepared by reaction of 4-fluorobenzoyl chloride with 2,5-bis(4-phenoxyphenyl)-1,3,4-oxadiazole in dichloromethane in the presence of aluminium chloride. Reaction of 2,5-bis[4-(4-fiuorobenzoyl)-(4-phenoxyphenyl)]-1,3,4-oxadiazole with diphenols in an aprotic solvent in the presence of potassium carbonate gave a series of aromatic poly(ether ketone oxadiazole)s. Films of the aromatic poly(ether ketone oxadiazole)s displayed good thermal stability, flexibility, and Ts s ranging from 172 to 218 C. The dielectric constants of the films were characterized as a function of relative humidity (RH).