Design of Precursor Polymers Assists the Processing of Poly(ether ether ketone) Membranes in Solvents

By examining the structural patterns of the imine monomers engaged in polycondensation, a series of poly(ether ether ketone) precursor polymers (PEEKi-N-acyl) modified with N-acyl Imine groups were designed in this work. Contrary to poly(ether ether ketone) (PEEK), these precursor polymers have superior solubility, enabling their production in solution and processing of membrane components. The membrane components’ substance could undergo an imine hydrolysis reaction in an acidic environment, turning them back into PEEK and giving them solvent resistance. In addition, the homogeneous polymer membranes of this series exhibit spontaneous pore formation under the action of ethanol, which was caused by solvent-induced internal stress relaxation. By utilizing the properties of this type of polymer, precursor polymers can be processed into PEEK sponge-like porous membranes, expanding the processing morphology and application range of PEEK.