Utilizing N-cyclohexyl imine as a protecting group enables faster fabrication of solvent-resistant PEK membranes

Semi-crystalline poly (ether ketone) (PEK) materials with intrinsic solvent resistance are ideal materials for the preparation of organic solvent nanofiltration (OSN) membranes. Although some precursor materials have been developed for soluble processing through group protection strategies, these precursors are difficult to hydrolyze, limiting their practical applications. In this work, we designed an easily hydrolyzable N-cyclohexyl-poly (ether ketone ether imide) (CYH-PEKEI) precursor that could be converted to PEK by acid treatment at 80°C within 1 h. The results showed that the prepared membrane was stable in various organic solvents, with a permeance of 1.29 L m −2  h −1 bar −1 in N, N-Dimethylformamide (DMF), a molecular weight cutoff of 320 g/mol, and good long-term operational stability. Additionally, the membrane demonstrated excellent aging resistance during variable temperature DMF operation. This work has stimulated the potential of PEK membranes for OSN applications by optimizing the precursor structure.