Influence of the membrane treatment on structure and properties of sulfonated poly(etheretherketone) semi-interpenetrating polymer network

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.

► Semi-IPN architecture is synthesized in the presence of DMAc.
► A fluorinated network and a linear S-PEEK are combined.
► Semi-IPN properties strongly depend on the synthesis solvent evaporation time.
► Morphology of the semi-IPN is influenced by the solvent evaporation conditions.
► Decrease of ionic domains distance confirms a structural modification of S-PEEK phase.