SYNTHESIS AND CHARACTERIZATION OF ISOMERIC BIPHENYL-CONTAINING POLY(ARYL ETHER BISKETONE)S .3. POLYMERS DERIVED FROM 3,4'-BIS(4-FLUOROBENZOYL)BIPHENYL AND BISPHENOLS

A series of high-molecular-weight amorphous and semicrystalline poly(a ryl ether bisketone)s were prepared from bisphenols and 3,4'-bis(4-flu orobenzoyl)biphenyl via nucleophilic aromatic substitution reactions. Model compound studies were carried out with several substituted monoh ydric phenols, 3,4'-bis(4-fluorobenzoyl)biphenyl and 3,4'-bis(4-chloro benzoyl)biphenyl. The dihalo-substituted aromatic ketones were synthes ized by the reaction of 3,4'-biphenyldicarboxylic acid with thionyl ch loride, followed by Friedel-Crafts acylation with the appropriate aryl halide. The required dicarboxylic acid was prepared starting from 4-b romotoluene and 3-methylcyclohexanone. Potassium carbonate mediated re action of the monomers in dimethylacetamide or diphenyl sulfone gave h igh-molecular-weight polymers in excellent yield. The glass transition temperatures of the polymers are in the 170 to 190-degrees-C range. I n addition, the polymers exhibit excellent thermal stability, as evide nced by both dynamic and isothermal thermogravimetric analysis, and af ford tough films by compression molding.