Synthesis of dendritic poly(arylene ether)s from a linear polymer core

Abstract

Three generations of dendritic poly(arylene ether)s with terminal 4-fluorophenylthio- or 4-fluorophenylsulfonyl groups have been synthesized. A new relatively high molecular weight bisphenol containing two pendent 4-fluorophenylthio groups was converted to a poly(arylene ether sulfone) to act as the dendritic core. A divergent approach with an activation/condensation sequence was used. The pendent 4-fluorophenylthio groups in the base polymer were oxidized with H 2O 2 in formic acid to give 4-fluorophenylsulfonyl groups in which the fluoride groups are then activated toward nucleophilic displacement reactions. The condensation step involved the reaction of a phenol containing two pendent 4-fluorophenylthio groups with the activated core polymer in the presence of Cs 2CO 3. Reiteration of these steps gave the subsequent generations. The polymers have high thermal stabilities by TGA analysis (5% weight loss>500 °C).