Graphene structured sulfonated poly(ether sulfone)s containing hexabenzocoronene for PEMFC

The novel sulfonated poly(ether sulfone)s containing hexabenzocoronene moiety that is partial graphene structure were synthesized and characterized their properties. Graphene is an allotrope of carbon and one-atom-thick planar sheets of sp²-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. Poly(arylene ether sulfone)s containing hexaphenyls on polymer backbone were synthesized by polycondensation and followed intra-cyclization by Friedel-Craft reaction with Lewis acid (FeCl₃) to form partial graphene structure. The sulfonation was taken selectively on hexabenzocoronen units with concentrated sulfuric acid. The structure properties of the sulfonated polymers were investigated by ¹H-NMR spectroscopy. The resulted ion exchange capacities (IEC) were 1.09~1.61 meq./g. The water uptakes were 8.84~15.27% at 30°C and 18.27%~42.38% at 80°C with changing the ion exchange capacities. The S-PDHTPE membranes exhibit proton conductivities (80 °C, RH 90) of 78.3~ 105.7 mS/cm compared with 106.2 mS/cm of Nafion 211^®.