Abstract: Excessive water swelling has been an important problem for proton exchange membranes materials, especially for sulfonated poly aryl ether ketone. In this article, a sulfonated polymer containing ester group was hydrolyzed to yield carboxylic side group on its side chain, then the polymer was blended with polyvinyl alcohol and heat-treated to obtain crosslinked blend membranes. The results showed that Tg of the crosslinked membrane was increased significantly suggesting the presence of crosslinking reaction in the polymers. At 100 ℃, the proton conductivity, water uptake and swelling ratio of the crosslinked membranes are in the ranges of 0.072~0.065 S/cm， 51%~89%， and 19%~30%, respectively. Both the water uptake and swelling rate of the membrane decreased in a certain degree. This method is promising for the preparation of sulfonated poly arylene ether based proton exchange membrane with improved overall performance.

Key words: proton exchange membranes, crosslink, carboxyl group