Characterization of LDPE/polystyrene cation exchange membranes prepared by monomer sorption and UV radiation polymerization

Low-density polyethylene (LDPE)/polystyrene (PS) cation exchange membranes were prepared using the monomer sorption method and UV radiation polymerization. In the preparation method, reaction behaviors during polymerization and sulfonation were investigated. The prepared membranes were characterized in terms of physical and electrochemical properties, exhibiting reasonable mechanical properties for an ion exchange membrane with weight gain (Wr) of above 0.3. DSC studies and FE-SEM image revealed the formation of a homogeneous membrane. The resulting membrane showed membrane electrical resistance (MER) of below 1.0 Ω cm2 and ion exchange capacity of 1.8 meq./g dry membrane. Both the current–voltage and the chronopotentiometric curves of the membranes suggest that LDPE/polystyrene membranes can be properly used at a high current density, and that the surface homogeneity of cation exchange sites in the membranes was comparable to that in commercial membranes.