Fully aromatic ionomers with precisely sequenced sulfonated moieties for enhanced proton conductivity
Li, Xuefeng LU ; Paoloni, Francois LU ; Weiber, Annika LU ; Jiang, Zhen-Hua and Jannasch, Patric LU
(2012)
In Macromolecules
45(3).
p.1447-1459
- Abstract
- Abstract in Undetermined
A series of six fully aromatic ionomers with precisely sequenced sulfonated sites along the polymer chains have been designed, prepared and characterized as proton-exchange membranes. Two straight-forward and efficient synthetic strategies based on Ullmann ether reactions and a Baeyer-Villiger rearrangement were devised to obtain bisphenol monomers with four or six phenylene units linked exclusively by ether bridges to avoid transetherification reactions. Polycondensations of these bisphenol monomers with mono- or disulfonated dihalide monomers gave high molecular weight poly(arylene ether), poly(arylene ether sulfone) and polyarylene ether ketone) homopolymers having microblock-like structures with sulfonated... (More) - Abstract in Undetermined
A series of six fully aromatic ionomers with precisely sequenced sulfonated sites along the polymer chains have been designed, prepared and characterized as proton-exchange membranes. Two straight-forward and efficient synthetic strategies based on Ullmann ether reactions and a Baeyer-Villiger rearrangement were devised to obtain bisphenol monomers with four or six phenylene units linked exclusively by ether bridges to avoid transetherification reactions. Polycondensations of these bisphenol monomers with mono- or disulfonated dihalide monomers gave high molecular weight poly(arylene ether), poly(arylene ether sulfone) and polyarylene ether ketone) homopolymers having microblock-like structures with sulfonated moieties separated by monodisperse non-sulfonated oligo(ether) spacers. The nanoscale morphology and properties of solvent cast membranes were closely related to the nature of the oligo(ether) spacers. Small angle X-ray scattering (SAXS) measurements showed intense scattering and very narrow ionomer peaks with second-order features for the polymers with the six-ring spacers. This clearly indicated that the controlled ionic sequencing enabled self-assembly of ionic aggregates with a much higher degree of organization in relation to a corresponding aromatic ionomer with a statistical distribution of the sulfonate groups. At an identical acid content, the ionomers containing meta ether linkages had lower glass transition temperatures than the all-para materials, leading to a higher water uptake and proton conductivity of the former ionomers. A membrane with an ion exchange capacity (IEC) of 2.05 meq g-1 and containing exclusively para linkages reached the same level of proton conductivity as Nafion® at 100% relative humidity (RH), and also had an excellent dimensional stability in boiling water. Under reduced RH, the conductivity of this membrane greatly exceeded that of a membrane based on a statistical copolymer analogue with a similar ionic content. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2295485
- author
- Li, Xuefeng
LU
; Paoloni, Francois
LU
; Weiber, Annika
LU
; Jiang, Zhen-Hua
and Jannasch, Patric
LU
- organization
- publishing date
- 2012
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- fuel cells, polymer electrolyte membranes, aromatic block copolymers, sequence-controlled polymerizations, SAXS
- in
- Macromolecules
- volume
- 45
- issue
- 3
- pages
- 1447 - 1459
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- wos:000300124200036
- scopus:84863174723
- ISSN
- 0024-9297
- DOI
- 10.1021/ma201599p
- language
- English
- LU publication?
- yes
- additional info
- Publication Date (Web): January 23, 2012 The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Polymer and Materials Chemistry (LTH) (011001041)
- id
- 47446245-f173-4050-8194-e8e101257673 (old id 2295485)
- alternative location
- http://pubs.acs.org/doi/abs/10.1021/ma201599p
- date added to LUP
- 2016-04-01 10:36:58
- date last changed
- 2022-03-27 17:56:08
@article{47446245-f173-4050-8194-e8e101257673,
abstract = {{Abstract in Undetermined<br/>A series of six fully aromatic ionomers with precisely sequenced sulfonated sites along the polymer chains have been designed, prepared and characterized as proton-exchange membranes. Two straight-forward and efficient synthetic strategies based on Ullmann ether reactions and a Baeyer-Villiger rearrangement were devised to obtain bisphenol monomers with four or six phenylene units linked exclusively by ether bridges to avoid transetherification reactions. Polycondensations of these bisphenol monomers with mono- or disulfonated dihalide monomers gave high molecular weight poly(arylene ether), poly(arylene ether sulfone) and polyarylene ether ketone) homopolymers having microblock-like structures with sulfonated moieties separated by monodisperse non-sulfonated oligo(ether) spacers. The nanoscale morphology and properties of solvent cast membranes were closely related to the nature of the oligo(ether) spacers. Small angle X-ray scattering (SAXS) measurements showed intense scattering and very narrow ionomer peaks with second-order features for the polymers with the six-ring spacers. This clearly indicated that the controlled ionic sequencing enabled self-assembly of ionic aggregates with a much higher degree of organization in relation to a corresponding aromatic ionomer with a statistical distribution of the sulfonate groups. At an identical acid content, the ionomers containing meta ether linkages had lower glass transition temperatures than the all-para materials, leading to a higher water uptake and proton conductivity of the former ionomers. A membrane with an ion exchange capacity (IEC) of 2.05 meq g-1 and containing exclusively para linkages reached the same level of proton conductivity as Nafion® at 100% relative humidity (RH), and also had an excellent dimensional stability in boiling water. Under reduced RH, the conductivity of this membrane greatly exceeded that of a membrane based on a statistical copolymer analogue with a similar ionic content.}},
author = {{Li, Xuefeng and Paoloni, Francois and Weiber, Annika and Jiang, Zhen-Hua and Jannasch, Patric}},
issn = {{0024-9297}},
keywords = {{fuel cells; polymer electrolyte membranes; aromatic block copolymers; sequence-controlled polymerizations; SAXS}},
language = {{eng}},
number = {{3}},
pages = {{1447--1459}},
publisher = {{The American Chemical Society (ACS)}},
series = {{Macromolecules}},
title = {{Fully aromatic ionomers with precisely sequenced sulfonated moieties for enhanced proton conductivity}},
url = {{http://dx.doi.org/10.1021/ma201599p}},
doi = {{10.1021/ma201599p}},
volume = {{45}},
year = {{2012}},
}