Three phenylphosphine oxide (PPO) containing trifluorovinyl aryl ether monomers were synthesized and polymerized via thermal cyclodimerization affording perfluorocyclobutyl (PFCB) polymers containing PPO pendent groups. The new polymers exhibited moderate to high glass transition temperatures (T-g = 145-217 degrees C) and good thermal stability in nitrogen (5% weight loss, T-d > 402 degrees C). Copolymerization with traditional PFCB forming monomers such as 4,4'-(trifluorovinyloxy)biphenyl resulted in film forming transparent thermoplastic copolymers with improved solubility and further enhanced thermal stability. Semi-fluorinated PPO containing polymers of this type may find potential application as space environment durable materials. (c) 2005 Elsevier Ltd. All rights reserved.