High temperature polymer electrolyte membrane
fuel cells (HT-PEMFC) are constructed around phosphoric acid imbibed
polybenzimidazole membranes. The polybenzimidazoles comprise a large family of
engineering plastics, characterized by their superior thermomechanical
properties. The most common derivative in this family of materials is poly(2,2′-(m-phenylene)-5,5′-bibenzimidazole) (m-PBI). It can be readily synthesized in
polyphosphoric acid (PPA) by step-growth polymerization of isophthalic acid
(IPA) and 3,3´-diaminobenzidine (DAB) in stoichiometric amounts. The polymer is subsequently isolated, purified and dissolved
in an organic solvent (such as N,N-dimethylacetamide or N-methyl-2-pyrrolidone). Mechanically
robust films are obtained by solution casting, and
further equilibration in phosphoric acid yields the proton conducting
The physicochemical properties of the membrane
depends on the degree of polymerization (molecular weight) and the structural
purity of the obtained polymer. Both parameters are to a large extent
determined by the monomer purity. Monomer impurities makes it difficult to
accurately control the stoichiometry during synthesis, and inevitably introduces
structural defects. Controlling the monomer purity is particularly challenging
for DAB, which is highly oxidation sensitive.
The overall aim of this project is to correlate
monomer purity with the quality of the obtained polymer. More specifically, the
- To synthesize m-PBI using monomers with a well-characterized assay
- To characterize the obtained polymers with
respect to molecular weight and structural purity
- To correlate the molecular weight and
structural purity of the polymer to the monomer assay
Proposed DTU institute:
Energy (proposed supervisors): David Aili (email@example.com), Chemistry
(proposed supervisors): Charlotte Held Gotfredsen (firstname.lastname@example.org).
Company: Danish Power
Systems (www.daposy.dk), contact
person Allan Robertson Petersen (email@example.com).
Power Systems, founded in 1994 and located north of Copenhagen, Denmark, is a
dynamic development- and manufacturing company working in the fields of
chemistry and energy with primary focus on fuel cells. The company currently
has 24 employees.
Power Systems works with a fuel cell technology called HTPEM (High Temperature
Polymer Electrolyte Membrane fule cells) and manufactures the critical
component called a MEA (Membrane Electrolyte Assembly) in which electricity is
generated by a reaction between a hydrogen containing gas, typically based on
methanol- and air.
Power Systems is one of the very few companies in the world that can
manufacture the material, polybenzimidazole (PBI), which the fuel cell’s
polymer membrane is made of, making us incredibly competitive on the fuel cell
Power Systems has established a number of excellent R&D relationships with
leading universities and companies worldwide bringing us closer to the market.
This gives us a unique understanding of the individual needs, specifications
and requirements of our customers, and facilitates our effort in delivering
state of the art customized technology to our customers.
general information, contact Hans Aage Hjuler, CEO (firstname.lastname@example.org).