Development of highly phosphonated polymers for fuel cell membranes.
Författare
Summary, in English
Phosphonated polymers may show high intrinsic proton conductivities at low water contents provided that the local concentration of phosphonic acid groups is very high [1,2]. Moreover, the lower acidity of aryl- and alkylphosphonic acids in relation to sulfonic acids requires higher acid contents to reach high conductivities also at higher water contents. In this context, poly(vinylphosphonic acid) (PVPA) has emerged as an interesting component for fuel cell membranes because of its extremely high concentration of phosphonic acid, corresponding to 9.25 mmol –PO3H2 per g dry material. However, the high ionic content leads to complete water solubility as well as poor mechanical properties in the solid state. Consequently, it is necessary to develop synthetic strategies to efficiently immobilize the PVPA in the membranes before practical use.
We have previously immobilized PVPA by preparing various block and graft copolymers with PVPA segments [3]. These copolymers where found to self-assemble and form robust membranes with nanostructured morphologies and high proton conductivities. Very recently we have pursued a number of novel synthetic strategies towards different highly phosphonated membranes. These approaches include phosphonated norbornene copolymers prepared via ring opening metathesis polymerization (ROMP) [4], multiblock copolymers selectively grafted with PVPA via anionic polymerization [5], as well as block and graft copolymers containing the more acidic poly(tetrafluorostyrenephosphonic acid) via atom transfer radical polymerization (ATRP) [6]. Challenges and selected results on the synthesis and properties of these copolymers and membranes will be presented and discussed along with future prospects.
We have previously immobilized PVPA by preparing various block and graft copolymers with PVPA segments [3]. These copolymers where found to self-assemble and form robust membranes with nanostructured morphologies and high proton conductivities. Very recently we have pursued a number of novel synthetic strategies towards different highly phosphonated membranes. These approaches include phosphonated norbornene copolymers prepared via ring opening metathesis polymerization (ROMP) [4], multiblock copolymers selectively grafted with PVPA via anionic polymerization [5], as well as block and graft copolymers containing the more acidic poly(tetrafluorostyrenephosphonic acid) via atom transfer radical polymerization (ATRP) [6]. Challenges and selected results on the synthesis and properties of these copolymers and membranes will be presented and discussed along with future prospects.
Avdelning/ar
Publiceringsår
2014
Språk
Engelska
Publikation/Tidskrift/Serie
ECS Meeting Abstracts
Länkar
Dokumenttyp
Konferensbidrag
Förlag
Electrochemical Society
Ämne
- Chemical Sciences
Conference name
226th Meeting of the Electrochemical Society
Conference date
2014-10-05 - 2014-10-09
Conference place
Cancun, Mexico
Status
Published