New Attempt at Preparation of Fluorine-containing Poly(ether ketone)s in Supercritical Carbon Dioxide

Fluorine-containing poly(ether ketone)s was synthesized by the nucleophilic aromatic substitution reaction of 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane and 4,4'-bis(2,3,4,5,6-pentafluorobenzoyl) diphenyl ether in super-critical CO(2). Polymerizations were carried out at 80℃ for 6 hours under 5000 psi of CO(2) pressure, which was super-critical phase. Polymerization concentration was 0.5 g of polymer in 10 - 12 mL of CO(2). The polymer was not obtained in CO(2) due to the insolubility of both the potassium bisphenoxide and the polymer into CO(2). However, the polymer was formed by an addition of DMAc and NMP in CO(2), even though molecular weight was not so high. Very small amount of co-solvents which were immiscible with CO(2) was effective, and it was 1/20 - 1/25 amount of the solvent used in the conventional poly(ether ketone) synthesis. The polymerization mechanism was also discussed.