Achieving high proton conductivity for fuel cells based on chemically grafted poly(arylene ether ketone sulfone) and metal–organic frameworks

•UiO-66-NH2 were anchored onto organic polymer backbone by chemical bond.•Sulfonyl imides have the same proton dissociation ability as sulfonic acid groups.•Hybrid membranes showed good long-term stability and excellent proton conductivity. The sulfonated poly(arylene ether ketone sulfone) containing –NH2 groups (Am-SPAEKS) and UiO-66-NH2 were respectively used as organic matrix and fillers. Am-S-U hybrid membranes were prepared by chemically anchoring UiO-66-NH2 onto the polymer main chain of Am-SPAEKS by Hinsberg reaction. The UiO-66-NH2 and Am-S-U hybrid membranes were characterized by 1H NMR, FT-IR, PXRD and SEM. The proton conductivities of Am-S-U hybrid membranes (0.072 ∼ 0.088 S cm−1 at 30 °C and 0.125 ∼ 0.168 S cm−1 at 80 °C) were much higher than Am-SPAEKS (0.058 S cm−1 at 30 °C and 0.090 S cm−1 at 80 °C). The membranes showed good dimensional stability (swelling ratios