Synthesis of dendritic-linear copoly(arylene ether)s from a linear copolymer core

Three generations of dendritic-linear copoly(arylene ether)s containing aryl sulfide and aryl sulfone groups, and aryl fluoride terminal functionality, have been synthesized using the divergent approach and an activation/condensation sequence that involves oxidation of 4-fluorophenylthio groups and the displacement of the activated halide moiety by a phenolate ion. A copolymer was synthesized from a relatively high molecular weight bisphenol that contained two 4-fluorophenylthio groups, along with bisphenol-A, and reacted with bis(4-fluorophenyl) sulfone and Cs2CO3. This copolymer was oxidized with H2O2 in formic acid to obtain the linear copoly(arylene ether sulfone) with activated terminal groups. The dendrimer units were built up in a condensation/activation sequence as previously described using a phenol containing two 4-fluorophenylthio groups. All the polymeric products were obtained in relatively high yield (70–97%) and were characterized using NMR, SEC and HPLC. They showed excellent thermal properties (5% weight loss >450 °C by TGA) and narrow polydispersities (1.3–1.6), however, films made from third generation products were very brittle.