The influence of ion concentration on dynamic mechanical property, tensilestrength and thermal stability of ionomers based on sulfonated ethylene-proplenecopolymers has been investigated. The results show that the above properties are related to the struCture of the ionomers. The membranes, made of sulfonated ionomers containing Na+ and Mg2+, are used for selective separation of ethanol-water mixture byPervaporation. The effects of canon species and contents, feed solution complsition aswell as temperature ...