Preparation of Composites of Hyperbranched Aromatic Poly(ethersulfone)s Possessing Sulfonic Acid Terminal Groups and Epoxy Resin for Polymer Electrolyte

An AB 2 monomer, 2,6-bis( p-sodium sulfophenoxy) benzonitrile 1, was synthesized from 2,6-dichlrobenzonitrile and p-sodium hydroxybenzene sulfonic acid. The novel hyperbranched poly(ethersulfone) 2 was prepared from self-polycondensation of the AB 2 monomer using phosphorus pentoxide/methane sulfonic acid as the condensation agent. The obtained hyperbranched polymer had the sulfonic acid groups at the terminals existing in a large quantity. The weight-average molecular weight ( M w ) of the polymer was 27,000. This polymer was thermally stable until 275 °C. The composites 2 and epoxy resin were prepared, and it was found that they had proton transfer mobility. The proton flux of epoxy resin composites was higher than that of the composites prepared from 2 and PVA. The epoxy resin composites had good thermal properties and were stable up to 200 °C.