Kinking Matters: meta-Terphenyl Improves Hydroxide Conductivity of Mechanically Robust Fluorine-Free Poly(arylene piperidinium) Copolymers for Anion Exchange Membranes
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| Title: | Kinking Matters: meta-Terphenyl Improves Hydroxide Conductivity of Mechanically Robust Fluorine-Free Poly(arylene piperidinium) Copolymers for Anion Exchange Membranes |
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| Authors: | Mazumder, Kajari, Nederstedt, Hannes, Weber, Richard, Haraguchi, Shuichi, 1983, Neubert, Richard, Plamper, Felix A., Müller, Christian, 1980, Sommer, M. |
| Source: | ACS Applied Materials & Interfaces. 17(29):41978-41990 |
| Subject Terms: | polymer electrolyte membranes, hydroxide conductivity, anion exchange membranes, fluorine-free polymers, meta-terphenyl polymers, poly(arylene piperidinium) copolymers |
| Description: | Poly(arylene piperidinium) (PAP) polymers have emerged as promising candidates for applications as anion exchange membranes (AEMs) and have seen some commercial use in the form of PiperION by Versogen; however, PiperION contains fluorinated units to balance its ionic content. Fluorine-free variants are environmentally more friendly alternatives as recycling is facilitated. Herein, we report a series of four fluorine-free PAP membranes that are mechanically robust and feature moderate water uptake yet high ionic conductivity. p-Quaterphenyl (pQP) is copolymerized with either m- or p-terphenyl (m/pTP) and N-methyl-4-piperidone under superacid-catalyzed polyhydroxyalkylation conditions. The molar ratios of the reactants are adjusted to maintain a balance of solubility and flexibility of the polymers and to reach ion exchange capacities between 2.53 and 2.66 mequiv g -1 . The polymers exhibit thermal stability of Td,95 > 260 °C, Young’s moduli between 0.7 and 1.0 GPa, and ultimate tensile stresses of 50-60 MPa in the dry state. Additionally, under submersion tensile deformation, the Young’s moduli and ultimate tensile stresses are in the range 200-320 MPa and 15-22 MPa, respectively. The sample with an equimolar ratio of pQP and mTP was found to exhibit a robust nature with elongation up to 170% when subjected to submersion tensile deformation, thus showing attractive mechanical properties under relevant working conditions. Wet membranes show an ionomer SAXS peak in the range of 5 nm, suggesting clustering of water and ionic parts of the chain. High hydroxide conductivity of up to 197 mS cm -1 at 80 °C is observed. Such behavior is promising considering their water uptake of 85% at 80 °C as an upper limit, resulting in moderate areal and through-plane swellings of 100% and 55%, respectively. The results demonstrate that fluorine-free PAPs can be tuned to match important criteria of AEMs, including low water uptake, high dimensional and alkaline stability, and high hydroxide conductivity. |
| File Description: | electronic |
| Access URL: | https://research.chalmers.se/publication/547483 https://research.chalmers.se/publication/547483/file/547483_Fulltext.pdf |
| Database: | SwePub |
Nájsť tento článok vo Web of Science | Abstract: | Poly(arylene piperidinium) (PAP) polymers have emerged as promising candidates for applications as anion exchange membranes (AEMs) and have seen some commercial use in the form of PiperION by Versogen; however, PiperION contains fluorinated units to balance its ionic content. Fluorine-free variants are environmentally more friendly alternatives as recycling is facilitated. Herein, we report a series of four fluorine-free PAP membranes that are mechanically robust and feature moderate water uptake yet high ionic conductivity. p-Quaterphenyl (pQP) is copolymerized with either m- or p-terphenyl (m/pTP) and N-methyl-4-piperidone under superacid-catalyzed polyhydroxyalkylation conditions. The molar ratios of the reactants are adjusted to maintain a balance of solubility and flexibility of the polymers and to reach ion exchange capacities between 2.53 and 2.66 mequiv g -1 . The polymers exhibit thermal stability of Td,95 > 260 °C, Young’s moduli between 0.7 and 1.0 GPa, and ultimate tensile stresses of 50-60 MPa in the dry state. Additionally, under submersion tensile deformation, the Young’s moduli and ultimate tensile stresses are in the range 200-320 MPa and 15-22 MPa, respectively. The sample with an equimolar ratio of pQP and mTP was found to exhibit a robust nature with elongation up to 170% when subjected to submersion tensile deformation, thus showing attractive mechanical properties under relevant working conditions. Wet membranes show an ionomer SAXS peak in the range of 5 nm, suggesting clustering of water and ionic parts of the chain. High hydroxide conductivity of up to 197 mS cm -1 at 80 °C is observed. Such behavior is promising considering their water uptake of 85% at 80 °C as an upper limit, resulting in moderate areal and through-plane swellings of 100% and 55%, respectively. The results demonstrate that fluorine-free PAPs can be tuned to match important criteria of AEMs, including low water uptake, high dimensional and alkaline stability, and high hydroxide conductivity. |
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| ISSN: | 19448252 19448244 |
| DOI: | 10.1021/acsami.5c08476 |