Bis(pyridin-2-ylmethyl)amine-grafted poly(aryl alkylene)s with enhanced chemical stability and acid-base interactions for high-temperature proton exchange membranes
Zhao, Wenzhe ; Chen, Si LU ; Chen, Bin ; Wu, Yang ; Jannasch, Patric LU
and Yang, Jingshuai
LU
(2026)
In European Polymer Journal
255.
- Abstract
- Developing high-temperature proton exchange membranes (HT-PEMs) that simultaneously achieve high proton conductivity, strong phosphoric acid (PA) retention, and long-term chemical stability remains a major challenge, particularly due to PA-induced plasticization and radical-induced oxidative degradation. Here, we develop a side-chain engineering strategy to decouple PA-binding sites from the polymer backbone, aiming to enhance acid utilization while preserving structural integrity. A poly(terphenyl alkylene) precursor bearing bromopropyl side chains (PpT-Br) was synthesized via a facile superacid-catalyzed polymerization, followed by grafting of four representative nitrogen-containing moieties to systematically tune membrane properties.... (More)
- Developing high-temperature proton exchange membranes (HT-PEMs) that simultaneously achieve high proton conductivity, strong phosphoric acid (PA) retention, and long-term chemical stability remains a major challenge, particularly due to PA-induced plasticization and radical-induced oxidative degradation. Here, we develop a side-chain engineering strategy to decouple PA-binding sites from the polymer backbone, aiming to enhance acid utilization while preserving structural integrity. A poly(terphenyl alkylene) precursor bearing bromopropyl side chains (PpT-Br) was synthesized via a facile superacid-catalyzed polymerization, followed by grafting of four representative nitrogen-containing moieties to systematically tune membrane properties. The introduction of functional side chains enables well-defined microphase separation and strengthens acid-base interactions, thereby improving both proton transport and PA retention. Among the prepared membranes, the bis(pyridin-2-ylmethyl)amine-functionalized membrane exhibits the best overall performance. The bulky bis-pyridine units provide multiple hydrogen- bonding sites and steric protection, resulting in reduced dimensional swelling, enhanced acid retention, and improved resistance to radical-induced degradation. Notably, this membrane achieves a high proton conductivity of 81.0 mS cm−1 at 180 °C, while maintaining ∼89% acid retention after 200 h at 80 °C and 40% relative humidity. In addition, it demonstrates superior oxidative stability, retaining structural integrity during prolonged Fenton testing. Single-cell evaluation under dry H2/O2 conditions reveals a peak power density of 483 mW cm−2 at 200 °C, significantly outperforming a reference ether-containing polybenzimidazole (OPBI) membrane. These results highlight the critical role of side-chain architecture in regulating acid-polymer interactions, suppressing degradation, and improving overall membrane durability. This work provides molecular-level insights into the molecular design of chemically robust HT-PEMs and establishes a scalable platform for next-generation HT-PEM fuel cell applications. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/ce88a505-e7e8-4da2-a2c9-1f25891aae51
- author
- Zhao, Wenzhe
; Chen, Si
LU
; Chen, Bin
; Wu, Yang
; Jannasch, Patric
LU
and Yang, Jingshuai
LU
- organization
- publishing date
- 2026
- type
- Contribution to journal
- publication status
- published
- subject
- in
- European Polymer Journal
- volume
- 255
- article number
- 114874
- publisher
- Elsevier
- ISSN
- 0014-3057
- DOI
- 10.1016/j.eurpolymj.2026.114874
- language
- English
- LU publication?
- yes
- id
- ce88a505-e7e8-4da2-a2c9-1f25891aae51
- date added to LUP
- 2026-03-26 00:21:17
- date last changed
- 2026-06-12 09:30:17
@article{ce88a505-e7e8-4da2-a2c9-1f25891aae51,
abstract = {{Developing high-temperature proton exchange membranes (HT-PEMs) that simultaneously achieve high proton conductivity, strong phosphoric acid (PA) retention, and long-term chemical stability remains a major challenge, particularly due to PA-induced plasticization and radical-induced oxidative degradation. Here, we develop a side-chain engineering strategy to decouple PA-binding sites from the polymer backbone, aiming to enhance acid utilization while preserving structural integrity. A poly(terphenyl alkylene) precursor bearing bromopropyl side chains (PpT-Br) was synthesized via a facile superacid-catalyzed polymerization, followed by grafting of four representative nitrogen-containing moieties to systematically tune membrane properties. The introduction of functional side chains enables well-defined microphase separation and strengthens acid-base interactions, thereby improving both proton transport and PA retention. Among the prepared membranes, the bis(pyridin-2-ylmethyl)amine-functionalized membrane exhibits the best overall performance. The bulky bis-pyridine units provide multiple hydrogen- bonding sites and steric protection, resulting in reduced dimensional swelling, enhanced acid retention, and improved resistance to radical-induced degradation. Notably, this membrane achieves a high proton conductivity of 81.0 mS cm−1 at 180 °C, while maintaining ∼89% acid retention after 200 h at 80 °C and 40% relative humidity. In addition, it demonstrates superior oxidative stability, retaining structural integrity during prolonged Fenton testing. Single-cell evaluation under dry H2/O2 conditions reveals a peak power density of 483 mW cm−2 at 200 °C, significantly outperforming a reference ether-containing polybenzimidazole (OPBI) membrane. These results highlight the critical role of side-chain architecture in regulating acid-polymer interactions, suppressing degradation, and improving overall membrane durability. This work provides molecular-level insights into the molecular design of chemically robust HT-PEMs and establishes a scalable platform for next-generation HT-PEM fuel cell applications.}},
author = {{Zhao, Wenzhe and Chen, Si and Chen, Bin and Wu, Yang and Jannasch, Patric and Yang, Jingshuai}},
issn = {{0014-3057}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{European Polymer Journal}},
title = {{Bis(pyridin-2-ylmethyl)amine-grafted poly(aryl alkylene)s with enhanced chemical stability and acid-base interactions for high-temperature proton exchange membranes}},
url = {{http://dx.doi.org/10.1016/j.eurpolymj.2026.114874}},
doi = {{10.1016/j.eurpolymj.2026.114874}},
volume = {{255}},
year = {{2026}},
}