Graft‐crosslinked Copolymers Based on Poly(arylene ether ketone)‐gc‐sulfonated Poly(arylene ether sulfone) for PEMFC Applications

Abstract

Novel poly(arylene ether ketone) polymers with fluorophenyl pendants and phenoxide-terminated wholly sulfonated poly(arylene ether sulfone) oligomers are prepared via Ni(0)-catalyzed and nucleophilic polymerization, respectively, and subsequently used as starting materials to obtain graft-crosslinked membranes as polymer electrolyte membranes. The phenoxide-terminated sulfonated moieties are introduced as hydrophilic parts as well as crosslinking units. The chemical structure and morphology of the obtained membranes are confirmed by (1) H NMR and tapping-mode AFM. The properties required for fuel cell applications, including water uptake and dimensional change, as well as proton conductivity, are investigated. AFM results show a clear nanoscale phase-separation microstructure of the obtained membranes. The membranes show good dimensional stability and reasonably high proton conductivities under 30-90% relative humidity. The anisotropic proton conductivity ratios (σ(formula see text) ) of the membranes in water are in the range 0.65-0.92, and increase with an increase in hydrophilic block length. The results indicate that the graft-crosslinked membranes are promising candidates for applications as polymer electrolyte membranes.

Fluorine-Free Precise Polymer Electrolyte for Efficient Proton Transport: Experiments and Simulations

“…Furthermore, the conductivity of p5PhSA is higher than that of many other hydrocarbon-based PEMs reported in the literature, both at similar conditions and when other PEMs are at higher temperatures or hydration levels, Figure S4. 3,[8][9][10][18][19][20]43 The proton conductivity in p5PhSA is reversible with increasing and decreasing humidity (Figure S2), as is required for a fuel cell application. The conductivities of p5PhSA and Nafion 117 at 40 °C are also compared as a function of water content λ in Figure 2c; in this representation, p5PhSA outperforms Nafion 117 at all water contents.…”

“…This exceeds that of many other PEMs reported in the literature, and is significantly higher than the IEC of typical PFSA membranes, including Nafion 117 (0.91 mmol/ g). 1,3,8,9,[18][19][20] The glass transition temperature (T g ) of p5PhSA is 103 °C, and the thermal degradation temperature (T d ) is 215 °C , both high enough that p5PhSA may have the thermal and mechanical stability necessary to operate as a PEM. 13,17 While this T g is lower than many other hydrocarbon-based PEMs, it may allow for easier processing of p5PhSA at lower temperatures compared to polymers with phenyl groups in the backbone.…”

Multiblock copolymers based on poly(p-phenylene)-co-poly(arylene ether sulfone ketone) with sulfonated multiphenyl pendant groups for polymer electrolyte fuel cell (PEMFC) application

“…The stiff and rod-like chemical structure of the polymers confers exceptionally good mechanical toughness and chemical stability to the polymer. Moreover, the flexible hydrophobic poly(arylene ether) block gives rise to a nanophase-separated morphology [17][18][19][20].…”

Sulfonated poly (arylene ether sulfone)-graft-sulfonated poly (vinyl alcohol) proton exchange membranes: Improved proton selectivity

“…Currently, it is widely believed that the effective control of the internal phase structure of polymer is an important means to enhance PEM performance. 23,24 Compared with the traditional random sulfonated polymers, the graft sulfonated polymers have obvious hydrophilic/hydrophobic phase separation structure, which is easy to form a State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University, Chengdu, People's Republic of China continuous proton conduction channel in the membrane, so as to obtain high proton conductivity. 25,26 More importantly, it is favorable for restricting methanol permeation coefficient and enhancing the selectivity of the membrane simultaneously.…”