Sulfonated fluorinated-aromatic polymers as proton exchange membranes

Abstract

Abstract:In recent years, extensive research on the preparation and properties of proton exchange membranes (PEMs) has been realized. This article focusses on the recent studies on new PEM materials based on aromatic hydrocarbon polymers with sulfonated groups as hydrophilic domains and fluorinated groups as hydrophobic domains as alternatives to conventional perfluorinated polymers. It is necessary to improve the proton conductivity especially under low-humidity conditions and at high operating temperatures to break through the current aromatic PEM system. Hence, there is a need to develop new high-conductivity fuel cell ionomers with improved thermal, chemical, and electrochemical stability by designing a suitable polymer structure for PEM application.

Hydroquinone Based Sulfonated Copolytriazoles with Enhanced Proton Conductivity

“…In PEMs, water uptake, swelling ratio, mechanical property, proton conductivity, and oxidative stability are directly related to the phase separation between the hydrophilic and hydrophobic domains of the membrane . The phase morphology of the PTHQSH‐XX membranes was studied by scanning transmission electron microscopy (STEM), and the micrographs are presented in Figure .…”

“…This element also helps in increasing chemical and thermal stability while decreasing the crystallinity and water absorption of the polymers . Furthermore, fluorine helps in the formation of phase separated morphology, which significantly improved the proton conductivity . Therefore, many efforts have been made in the recent years to prepare fluorinated sulfonated copolymer membranes with good proton conductivity and suitable dimensional stability .…”

Hexafluoroisopropylidene based sulfonated new copolytriazoles: investigation of proton exchange membrane properties

“…The interconnection of the ionic clusters gradually increases with DS that eventually helps in better proton transport (47). The TEM micrographs showed small ionic clusters (20-35 nm) membranes form good microphaseseparated morphol ogy, because of the presence of highly hydrophobic 6F moieties in the polymer backbone (36,42).…”

Flexible Diazide Based Sulfonated Polytriazoles and Their Proton Exchange Membrane Properties

“…[21][22][23][24][25][26] The prepared polymers showed a good set of physical properties, e.g., high thermal and mechanical stability as well as high dimensional and oxidative stability relative to many other polyimides. [27,28] However, much work is still required in designing new polytriazoles with high proton conductivity. In our continued research on development of PEM materials, we observed that simple structural manipulation of the diamines resulted in polyimides with an altogether different set of physical properties.…”