A novel class of phenylphosphine oxide (PPO) containing perfluorocyclobutyl (PFCB) polymers has been developed for potential use as multifunctional materials in space environments. The reaction of p-BrArOCF = CF2 (for Ar = phenyl and biphenyl) with tert-butyllithium affords the lithium reagent smoothly below -20 degreesC. Subsequent substitution with phenylphosphonic dichloride provides the first bis(trifluorovinyl ether) monomers containing the PPO group. Polymerization proceeds thermally above 150 degreesC to give polymers that exhibit glass transition temperatures of 169 and 224 degreesC, respectively, and catastrophic weight loss by TGA in N-2 and air above 450 degreesC (10 degreesC/min). Copolymerization with bis(4,4'-trifluorovinyloxy)biphenyl affords film-forming transparent thermoplastic copolymers with high T-g (> 140 degreesC) and good thermal stability (> 450 degreesC). Initial evaluations with ground-based simulation of atomic oxygen (AO) rich space environments indicate that the PPO group imparts significant space durability to PFCB polymers.