The synthesis and characterization of poly (arylene ether) s containing the phosphine oxide unit along the backbone were investigated and unique properties derived from the presence of this moiety were identified. The preparation of crucial phosphine oxide containing monomers which would be susceptible to the desired nucleophilic aromatic substitution polycondensation was achieved via Grignard routes. Thus, bis (4-fluorophenyl)phenyl phosphine oxide and bis (4-fluoropheny) methyl phosphine oxide were found to undergo successfully polymerization by a nucleophilic displacement reaction with aromatic bisphenols in the presence of potassium carbonate and dipolar aprotic solvents. The resulting poly (arylene ether phosphine oxide) s had glass transition temperatures ranging from 195 to 285°C depending on the rigidity of the bisphenol and the pendant group on the phosphorus containing monomers. Many properties were typical of their poly (arylene ether sulfone) and poly (arylene ether ketone) counterparts, including excellent hydrolytic, thermal and oxidative stability. Good dimensional stability and mechanical properties were also obtained. Physical blends and statistical copolymers, as well as polymers of controlled molecular weight and functionality, were also prepared via conventional techniques, yielding novel phosphorus containing compositions. Unique features of these poly (arylene ether phosphine oxide) s (PEPO) were discovered initially by thermogravimetric analysis in air. All PEPO gave significant amounts of phosphorus containing char at temperatures where other engineering polymers were completely volatilized. This behavior was related to the very improved self-extinguishing behavior of all the phosphorus containing systems. Unlike most phosphorus containing polyphosphonates described in the literature, the phosphorus-aryl carbon bond was hydrolytically stable. Additionally, these PEPO materials were much more resistant to aggressive oxygen plasma environments due solely to unique oxidized phosphorus surface layers formed upon exposure to these harsh conditions. Finally, metal complexation through the phosphine oxide unit was discovered to be a novel way to modify polymer properties. / Ph. D.