High Porosity Poly(ether ketone ketone): Influence of Solvents on Foam Properties

Poly(ether ketone ketone) (PEKK) is a semicrystalline high-performance polymer with exceptional mechanical properties, high continuous operation temperature, and is insoluble in most common solvents. Porous PEKK, desired for biomedical applications, is produced by a high-temperature thermally induced phase separation process using PEKK solutions in two high boiling aprotic solvents, 4-phenylphenol and 9-fluorenone, with concentrations up to 20 wt.%. It is demonstrated that the solvent choice has a pronounced influence on the phase separation behavior, which determines the foam morphology, physical and mechanical properties of PEKK foams. Porous PEKK with porosities ranging from 70% to 90%, specific surface areas up to 194 m² g⁻¹ and elastic moduli ranging from 35 to 100 MPa are produced.