The Penn State Research Foundation

Michael A Hofmann

Harry R Allcock

Serguei N Lvov

Daniel T Welna

Maher E Andrew

Digby McDonald

Catherine M Ambler

Richard M Wood

Xiang Y Zhou

The invention relates to sulfonimide bearing phenolic compounds and the use of those compounds to produce polyphosphazenes functionalized by one or more of those compounds alone, or in combination with cosubstituents. The invention also relates to blends of sulfonimide functionalized phosphazene polymers with other polymers, membranes formed of the functionalized polymers, and the use of those membranes in devices such as fuel cells.

Synthesis of polyphosphazenes with sulfonimide side groups

Proton conducting membranes having improved resistance to methanol crossover are provided, along with methods for their manufacture. In a preferred embodiment, the polymeric membranes are formed by (a) dissolving a polymer, preferably a polyphosphazene, in an organic solvent to form a polymer solution; (b) adding an oxyacid to the polymer solution; (c) optionally, adding water to the polymer solution, preferably in a molar ratio equivalent to the oxyacid; (d) optionally, concentrating the polymer solution; (e) casting the polymer solution on a casting surface, such as one formed of or coated with TEFLON&trade;; and (f) removing the organic solvent, so as to form the polymeric membrane. A particularly useful application for these polymeric membranes is in fuel cells, such as those wherein methanol and oxygen are converted into electrical energy.

Proton conducting polymer membranes

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Brookhaven, PA, United States of America

Michael A Hofmann