To prepare a cross-linked proton exchange membrane with low methanol permeability and high proton conductivity, poly (vinyl alcohol) is first blended with sulfonated poly (arylene ether ketone) bearing carboxylic acid groups (SPAEK-C) and then heated to induce a cross-linking reaction between the carboxyl groups in SPAEK-C and the hydroxyl groups in PVA Fourier transform infrared spectroscopy is used to characterize and confirm the structure of SPAEK-C and the cross-linked membranes The proton conductivity of the cross-linked membrane with 15% PVA in weight reaches up to 0 18 S cm(-1) at 80 degrees C (100% relative humidity), which is higher than that of Nafion membrane, while the methanol permeability is nearly five times lower than Nafion The ion-exchange capacity, water uptake and thermal stability are investigated to confirm their applicability in fuel cells (C) 2009 Professor T Nejat Veziroglu Published by Elsevier Ltd All rights reserved