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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. [ABSTRACT FROM AUTHOR]

Abstract: Semi-Interpenetrating Polymer Networks (semi-IPNs) combining a fluorinated network with a linear sulfonated poly(etheretherketone)(S-PEEK) were synthesized in presence of DMAc as solvent. The effects of the evaporation conditions of solvent during fabrication process on water swelling, proton conductivity and thickness measurements suggest a morphology modification of the semi-IPN. SAXS and SANS measurements confirmed the structural modification of the S-PEEK and fluorinated phases leading to a decrease of the hydrophilic/hydrophobic domain nanoseparation when the drying time increases along with lower water swelling ability, proton conductivity, water self-diffusion coefficient. On the contrary, the immersion time of this semi-IPN into an acid solution to carry out the cation exchange does not affect its morphology. [Copyright &y& Elsevier]

Abstract: The purpose of this study has been to develop new proton-exchange membranes based on semi-interpenetrating polymer network (semi-IPN) architectures for application in polymer electrolyte fuel cells. A series of semi-IPNs combining a fluorinated hexane network and a linear sulfonated poly(aryl ether ether ketone) (SPEEK) has been obtained by varying the SPEEK content from 50 to 80wt.%. A telechelic functionalized acrylate oligomer was obtained by acrylation of α,ω-fluorinated hexanediol, while SPEEK was synthesized by polycondensation of sulfonated difluorobenzophenone with the bisphenol 6F. These semi-IPN membranes have been characterized by infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy, and small-angle X-ray scattering. A semi-IPN containing 60wt.% SPEEK has been tested as a fuel cell membrane. [Copyright &y& Elsevier]