Properties of polymer electrolyte membranes prepared by blending of sulfonated polystyrene-lignosulfonate

Electrolyte polymer membrane widely used in pemfc and dmfc is a perfluorosulfonated membrane such as nafion. this membrane material exhibits good chemical stability and proton conductivity,but it is very expensive and difficult to recycle. it has high cross-over methanol in dmfc that causes the decrease efficiency and performance of fuel cell,so that the electrolyte polymer membrane with low cross-over methanol has been needed to substitute nafion membrane. one of the materials used as a polymer electrolyte membrane is polyblends of a sulfonated polystyrene-lignosulfonate (sps-ls). these polyblends have been prepared by casting polymer solution and characterized as a polyelectrolyte membrane for dmfc. sps was prepared by sulfonation of polystyrene with acetyl sulfate used as a sulfonating agent. the membranes of sps-ls were characterized by analysis of functional groups,mechanical properties,and methanol permeability. the maximum mechanical properties of the sps-ls membrane were observed in ls ratio of 7.5%. however,the methanol permeability of membrane increases as the increase of ls ratio in sps-ls membranes. the properties of membranes,especially the mechanical property and methanol permeability close to that of nafion® 117 membrane,so the sps-ls membrane is highly potential used as the electrolyte membrane for direct methanol fuel cell. © 2012 published by lppm itb.