In order to meet the requirements of proton exchange membranes in direct methanol fuel cells (DMFCs)

sulfonated poly(aryl ether ketone) bearing pendant sulfonic acid groups/PVA (S-SPAEK/PVA) crosslinked composite membranes with different contents of PVA are prepared by solution blend method.S-SPAEK/PVA crosslinked composite membranes are obtained by a heating reaction at 120 ℃.FTIR spectra show that crosslinked structure is formed due to the bonds of COS between the sulfonic acid groups on S-SPAEK and hydroxyl groups on PVA.The swelling ratio both at length and thickness

water retention capacity and methanol permeability of S-SPAEK/PVA cross-linked membranes are improved due to the introduction of PVA.The water diffusion coefficient of the S-SPAEK/PVA (85/15) cross-linked membrane reaches 2.910-9 cm2/s which is lower than that of pure S-SPAEK membrane (3.110-8 cm2/s).The methanol diffusion coefficient values of S-SPAEK/PVA (85/15) cross-linked membranes at 25 ℃ and 60 ℃ reach 2.610-7cm2/s and 3.910-7 cm2/s

respectively

which are obviously lower than 8.110-7 cm2/s and 14.510-7 cm2/s of pure S-SPAEK membranes under the same test conditions.It can be obviously seen that the methanol diffusion coefficient of S-SPAEK/PVA cross-linked membranes decreases with increasing the content of PVA.Although the proton conductivities of S-SPAEK/PVA (85/15) cross-linked membranes are decreased

they still reach 0.055 S/cm at 25 ℃ and 0.083 S/cm at 80 ℃

respectively.All the results indicate that the S-SPAEK/PVA (85/15) crosslinked composite membranes are promising as proton exchange membranes for DMFCs applications.