Synthesis of organosoluble aromatic poly(ether ketone)s with short perfluoroalkyl groups in the side chains

Three types of 9,9-bis(4-hydroxyphenyl)fluorene-based diols reacted with 4,4′-difluorobenzophenone via nucleophilic substitution polymerization to afford the corresponding aromatic poly(ether ketone)s. The resulting polyketones have excellent solubility in typical organic solvents, such as THF, CHCl₃, and NMP. They also have good thermal stability above 400 °C (T_d10). In particular, the surface tension of the polyketone, which has four C₄F₉ groups per repeating unit, is 18.7 mN/m, which is equal to that of PTFE. The introduction of propylene linkers and many C₄F₉ groups per repeating unit was effective at improving water/oil repellency.