Synthesis of sulfonated fluorenyl-containing poly(ether ether ketone ketone)s and their blends with an amino-functionalized poly(ether ether ketone) for fuel cell applications

A new family of sulfonated fluorenyl-containing poly(ether ether ketone ketone)s (SFPEEKKs) were successfully synthesized through a mild postsulfonation in concentrated sulfuric acid at room temperature. Further, a series of "molecule-enhanced" blend membranes were prepared based on SFPEEKKs and an amino-functionalized poly(ether ether ketone) by the solution casting method. These blend membranes generally showed higher thermal stability, lower swelling ratio and methanol permeability and superior mechanical properties in comparison with pristine SFPEEKK membranes. The results showed that some blend membranes may be promising proton exchange membranes for fuel cell applications.