Synthesis and Characterization of Partially Fluorinated Polybenzoxazine Resins Utilizing Octafluorocyclopentene as a Versatile Building Block

Two new fluorinated diamine-based benzoxazines using octafluorocyclopentene (OFCP) as a building block have been developed. Monomers were synthesized via two distinct synthetic procedures utilizing the facile nucleophilic addition–elimination reaction of OFCP with phenols amenable to a multigram scale-up. The structure elucidation of both monomers was confirmed by ¹H, ¹⁹F, and ¹³C NMR, ATR-FTIR, and high-resolution mass spectrometry. Benzoxazine networks were prepared by a thermally mediated ring-opening polymerization. ATR-FTIR analysis was utilized to monitor the ring-opening reaction of the monomers. The resulting two cured resins exhibit the combined excellent properties of low dielectric constants (<i>k</i> = 3.2–2.6), excellent thermal stability, and high char yields which are suitable for many applications such as flame-resistant materials as well as aerospace and microelectronic industries