Effect of a neutral fluorinated network on the properties of a perfluorosulfonic acid ionomer as proton exchange membrane

• A new series of semi-IPNs based on Aquivion has been synthesized.
• Aquivion® is mechanically strengthened by association with a fluorinated network.
• These membranes were evaluated at 105 °C in fuel cell operation.

Proton and water transport properties as well as water sorption, thermomechanical properties, and morphology of a new series of semi-Interpenetrating Polymer Network (semi-IPN) combining perfluorosulfonated ionomer (Aquivion®) with a neutral fluorinated network of composition ranging between 10 and 50 wt% have been studied. When less than 20 wt% of neutral fluorinated network are included, water and proton transport properties of semi-IPNs are enhanced compared to that of Aquivion®, despite of their decrease of ion exchange capacity and their capacity to absorb water. Thermal and chemical stabilities are maintained very close to those of Aquivion®. In addition, these new materials show similar performances in fuel cell operation at 105 °C compared to those of Aquivion®. That evidences that perfluorosulfonated ionomer can be strengthened by association with a neutral fluorinated network.