Poly(N,N-diallylazacycloalkane)s for anion-exchange membranes functionalized with N-spirocyclic quaternary ammonium cations
Olsson, Joel S. LU ; Pham, Thanh Huong LU and Jannasch, Patric LU
(2017)
In Macromolecules
50(7).
p.2784-2793
- Abstract
- The alkaline stability of organic cations tethered to anion-exchange membranes (AEMs) is essential for the long-term performance of alkaline membrane fuel cells and electrolyzers. Here, we have prepared and studied the thermal and alkaline stability of a series of polyelectrolytes functionalized with N-spirocyclic quaternary ammonium (QA) cations. N,N-diallyl azacycloalkane quaternary salts were readily synthesized by diallylation of pyrrolidine, piperidine, azepane, and morpholine, respectively. These monomers were employed in radical-initiated cyclo-polymerizations to obtain the target poly(N,N-diallyl azacycloalkane)s. 1H NMR spectroscopy revealed that the stability of the polyelectrolytes... (More)
- The alkaline stability of organic cations tethered to anion-exchange membranes (AEMs) is essential for the long-term performance of alkaline membrane fuel cells and electrolyzers. Here, we have prepared and studied the thermal and alkaline stability of a series of polyelectrolytes functionalized with N-spirocyclic quaternary ammonium (QA) cations. N,N-diallyl azacycloalkane quaternary salts were readily synthesized by diallylation of pyrrolidine, piperidine, azepane, and morpholine, respectively. These monomers were employed in radical-initiated cyclo-polymerizations to obtain the target poly(N,N-diallyl azacycloalkane)s. 1H NMR spectroscopy revealed that the stability of the polyelectrolytes in 2 M KOD/D2O solutions critically depended on the ring size and the absence of additional heteroatoms in the ring. Thus, poly(N,N-diallyl piperidinium) showed the highest alkaline stability, with only minor signs of degradation at 120 °C after 14 days, while the polyelectrolytes based on the morpholine and azepane rings clearly degraded via both Hofmann elimination and ring-opening substitution already at 90 °C. Crosslinked water non-soluble AEMs were prepared by copolymerizing N,N-diallyl piperidinium chloride with methylbenzyldiallyl ammonium groups tethered to poly(phenylene oxide). These transparent and mechanically robust AEMs reached high OH– conductivities, above 0.1 S cm-1 at 80 °C. The present work demonstrate the high alkaline stability of suitably configured N-spirocyclic QA cations, which will open up new prospects for readily accessible high performance polyelectrolytes and membranes. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2a6a9e44-0cf7-42df-8217-ebb6f5d4b0bc
- author
- Olsson, Joel S.
LU
; Pham, Thanh Huong
LU
and Jannasch, Patric
LU
- organization
- publishing date
- 2017
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Macromolecules
- volume
- 50
- issue
- 7
- pages
- 2784 - 2793
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- scopus:85017653598
- wos:000399263900019
- ISSN
- 0024-9297
- DOI
- 10.1021/acs.macromol.7b00168
- language
- English
- LU publication?
- yes
- additional info
- Publication Date (Web): March 31, 2017
- id
- 2a6a9e44-0cf7-42df-8217-ebb6f5d4b0bc
- date added to LUP
- 2017-03-17 23:47:34
- date last changed
- 2022-04-24 22:48:16
@article{2a6a9e44-0cf7-42df-8217-ebb6f5d4b0bc,
abstract = {{The alkaline stability of organic cations tethered to anion-exchange membranes (AEMs) is essential for the long-term performance of alkaline membrane fuel cells and electrolyzers. Here, we have prepared and studied the thermal and alkaline stability of a series of polyelectrolytes functionalized with <i>N</i>-spirocyclic quaternary ammonium (QA) cations. <i>N</i>,<i>N</i>-diallyl azacycloalkane quaternary salts were readily synthesized by diallylation of pyrrolidine, piperidine, azepane, and morpholine, respectively. These monomers were employed in radical-initiated cyclo-polymerizations to obtain the target poly(<i>N</i>,<i>N</i>-diallyl azacycloalkane)s. <sup>1</sup>H NMR spectroscopy revealed that the stability of the polyelectrolytes in 2 M KOD/D<sub>2</sub>O solutions critically depended on the ring size and the absence of additional heteroatoms in the ring. Thus, poly(<i>N</i>,<i>N</i>-diallyl piperidinium) showed the highest alkaline stability, with only minor signs of degradation at 120 °C after 14 days, while the polyelectrolytes based on the morpholine and azepane rings clearly degraded via both Hofmann elimination and ring-opening substitution already at 90 °C. Crosslinked water non-soluble AEMs were prepared by copolymerizing <i>N</i>,<i>N</i>-diallyl piperidinium chloride with methylbenzyldiallyl ammonium groups tethered to poly(phenylene oxide). These transparent and mechanically robust AEMs reached high OH<sup>–</sup> conductivities, above 0.1 S cm<sup>-1</sup> at 80 °C. The present work demonstrate the high alkaline stability of suitably configured <i>N</i>-spirocyclic QA cations, which will open up new prospects for readily accessible high performance polyelectrolytes and membranes.}},
author = {{Olsson, Joel S. and Pham, Thanh Huong and Jannasch, Patric}},
issn = {{0024-9297}},
language = {{eng}},
number = {{7}},
pages = {{2784--2793}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Macromolecules}},
title = {{Poly(<i>N</i>,<i>N</i>-diallylazacycloalkane)s for anion-exchange membranes functionalized with <i>N</i>-spirocyclic quaternary ammonium cations}},
url = {{http://dx.doi.org/10.1021/acs.macromol.7b00168}},
doi = {{10.1021/acs.macromol.7b00168}},
volume = {{50}},
year = {{2017}},
}