Phenylphosphonic acid functionalized poly [aryloxyphosphazenes]

A method for the synthesis of phenylphosphonic acid functionalized poly[aryloxyphosphazenes] is described. Diphenyl chlorophosphate was used as the phosphonating agent and was allowed to react with lithio-functionalized aryloxyphosphazenes, followed by treatment with aqueous sodium hydroxide. Subsequent acidification with aqueous hydrochloric acid yielded phenylphosphonic acid functionalized poly [aryloxyphosphazenes]. These polymers are candidates for use as proton-conducting membranes in fuel cells.