Morphology and Transport Properties of Phosphonium-containing Styrenic Ionomers with Random Charge Placement

Alkaline fuel cell (AFC) technology is currently of interest for portable power supplies due in part to the use of less expensive non-noble metals (nickel, iron, cobalt) as the catalyst material. Wide-spread use of the AFC has been prevented by the use of aqueous KOH as the liquid electrolyte, easily poisoned by CO$_{2}$. Development of an semipermeable polymeric alkali anion exchange membrane (AEM) would significantly improve the usefulness of AFCs. We have synthesized a series of random copolymers of styrene and p-vinylbenzyl-trimethylphosphonium chloride, via RAFT polymerization. Detailed $^{1}$H-NMR analysis of the polymerization conditions allowed us to refine our approach and generate materials with random monomer addition. $^{1}$H-NMR was also used to quantify ion contents, which range from 15 mol{\%} to 100 mol{\%}. In this presentation, we will review the synthesis and characterization of these novel cationomers, and then report on their anion transport characteristics and morphological behavior as characterized via SAXS and TEM.