Effect of Cellular Structure Controlled by Polysiloxane‐Polyether Surfactant on Mechanical Properties of Rigid Polyimide Foam

Polyimide foam, a lightweight porous material with thermal insulation and acoustic absorption properties, has demonstrated significant potential for aerospace applications. However, advancing technologies urgently require enhanced mechanical performance in these materials. This study introduces a novel method for preparing rigid polyimide foam (RPIF) by adjusting the content of the surfactant polysiloxane‐polyether copolymer (trade name AK8805). The impact of microscopic pore structures on the mechanical properties of RPIF is analyzed. Results show that while AK8805 does not significantly alter the molecular structure or thermal properties, it enhances porosity, closed‐cell ratio, and pore distribution, optimizing mechanical performance. At 6 wt% AK8805, RPIF achieves a compressive strength of 5.45 MPa and modulus of 60.74 MPa. Low porosity, high closed‐cell ratio, and uniform pore distribution significantly improve load transfer and mechanical properties. This study provides an effective approach for optimizing structural foams for advanced applications.