High‐Performance Polymer Foams by Thermally Induced Phase Separation

Macroporous, low‐density polyetheretherketone, polyetherketoneketone, and polyetherimide foams are produced using a high‐temperature, thermally induced phase separation method. A high‐boiling‐point solvent, which is suitable to dissolve at least 20 wt% of these high‐performance polymers at temperatures above 250 °C, is identified. The foam morphology is controlled by the cooling procedure. The resulting polymer foams have porosities close to 80% with surface areas up to 140 m2g−1and elastic moduli up to 97 MPa.