Aramid compositions of improved solubility and flame retardancy

Aramid polymers, e.g., those derived from p-phenylene diamine and terephthaloyl chloride, can have their solubility properties and flame retardancy enhanced by the incorporation therein of a moiety derived from a bis(aminophenoxyphenyl) phosphine oxide, e.g., bis(3-aminophenoxy-4'-phenyl) phenylphosphine oxide.