Synthesis and properties of poly[2,2′-(4,4′-(2,6-bis(phenoxy) benzonitrile))-5,5′-bibenzimidazole] for proton conducting membranes in fuel cells

Sulfonated poly(phenylsulfone)/fluorinated polybenzoxazole nanofiber composite membranes for proton exchange membrane fuel cells

“…Meanwhile the wellknown drawbacks of Nafion have motivated researchers to develop candidate PEMs to alternate Nafion. PEMs such as sulfonated poly(phenylene)s [2], poly(arylene ether ketone)s [3e5], poly(arylene ether)s [6,7], polymides [8,9], sulfonated PBT [10] and PBI [11], sulfonated poly(-phenylsulfone) (SPPSU) [12e15] have been developed. Although SPPSU have high thermal stability, excellent mechanical strength, and strong resistance to membrane decomposition in acidic water media, the drawbacks such as high water uptake, large dimensional change, and poor proton conductivity at dehumidified conditions are still need to be improved.…”

Anhydrous Proton‐Conducting Polymers for High‐Temperature PEMFCs

“…Methanol permeation measurements were reported using a diffusion cell with a liquid methanol solution as feed at the source side of the separating membrane and pure water in the receiving chamber at the other side [114,158,160,161,166]. This is a simple method to determine the methanol permeability via diffusion, which would be the dominating mechanism in case of a zero electro-osmotic drag coefficient for PBI membranes.…”

“…4.9)[114]. The introduction of fluorine into the backbone of the polymers has significant positive effects on their chemical oxidation stability demonstrated by Fenton test.…”

Polycondensation of structurally divergent tetraamine monomers with dicarboxylic acids to synthesize polybenzimidazole copolymers for polymer electrolyte membranes

“…To meet the application booms described above, the synthesis of PBIs with a variety of structures so that the properties can be readily manipulated became the prime objective for researchers working in this area . Polycondensation of a tetraamine with dicarboxylic acid (DCA) yields PBI; in the literature 3,3′,4,4′‐tetraaminobiphenyl (TAB) is polymerized with varieties of DCA structures to modulate the PBI properties.…”

“…A large number of DCAs with a variety of structures have been used to make PBIs. The primary objectives of the structural variation of the DCAs were mainly twofold: make soluble and hence easily processable PBI since otherwise PBI is difficult to process, and control PBI properties such as rigidity, thermal stability, basicity, chain folding etc . The most common PBI structures known are meta ‐PBI ( m ‐PBI), para ‐PBI ( p ‐PBI), sulfonated PBI, pyridine based PBI, oxy‐PBI etc.…”