Linear poly(arylene ether)s with pendant phenylsulfonyl groups: Nucleophilic aromatic substitution activated from the meta position

The synthesis, characterization, and nucleophilic aromatic substitution (NAS) behavior of 3,5-difluorophenyl sulfone, 3, are reported. The reactivity of the electrophilic sites, activated by only a phenylsulfonyl group located in the meta position, in 3 was probed via NMR spectroscopy and model reactions and was determined to be sufficient to undergo NAS reactions. Displacement of the first fluoride atom in 3, with the phenoxide ion derived from p-cresol, resulted in a significant decrease in reactivity for displacement of the second fluoride atom, however, not to such an extent as to prevent its displacement under more vigorous conditions. Confirmation of an SNAr mechanism was provided by H-1 and C-13 NMR data on the model compounds. High molecular weight, amorphous poly(arylene ether)s, bearing a pendant phenylsulfonyl group, were prepared via the reaction of 3 with a variety of bisphenols under typical NAS conditions. The glass transition temperatures (T-g) ranged from 136 to 175 degrees C while the 10% weight loss temperatures ranged from 530 to 590 degrees C under nitrogen and from 507 to 562 degrees C in air.