In this work was studied the effect of sulfonation of styrene-acrylic ester and of titanium dioxide nanoparticles on the proton exchange membranes. It was evaluated the physicochemical characterization of membranes, such as, the water uptake capacity, ion exchange capacity, the mechanic properties of stress/strain, and the chemical functional groups present in the membrane structure by FTIR analysis. Water uptake increases with increasing the time of sulfonation reaction, reaching 60.9% after 8 hours of sulfonation; while, ion exchange capacity of loaded-sulfonated membrane increases with increasing the time of sulfonation reaction and with increasing the TiO 2 load, reaching 0.39 meq/g for 8 hours and 4% TiO 2. It was observed that the elasticity of the synthesized membranes increases with increasing the time of sulfonation reaction, and it decreases with the addition of the TiO 2 load. This physicochemical property set allows to consider the membrane with high potential of application in the fuel cells area.