Synthesis of Proton Exchange Membranes from Natural Rubber

In this work proton exchange membranes were synthesized from natural rubber. This polymer was modified by the process of sulfonation, vulcanization and addition of titanium dioxide as inorganic load. The membranes characterization was evaluated by water uptake, ion exchange capacity and stress–strain tests. Sulfonated membranes have highest water uptake due to the introduction of sulfonic groups in the polymer structure. Meanwhile, ion exchange capacity increases with increasing of titanium dioxide (TiO2) from 0.16 to 0.23 meq/g¬. Moreover, the loaded membranes with titanium dioxide have lowest water uptake due to the TiO2 behavior as a ceramic filler that decreased the membrane free volume and its swelling capacity. The above results indicate natural rubber is a good alternative for application on fuel cells