Preparation and Properties of High-Temperature-Resistant, Lightweight, Flexible Polyimide Foams with Different Diamine Structures.

Polyimide foam (PIF) is a rising star in high-end applications such as aerospace thermal insulation and military sound absorption. However, the basic rule on molecular backbone design and uniform pore formation of PIF still need to be explored. In this work, polyester ammonium salt (PEAS) precursor powders are synthesized between alcoholysis ester of 3, 3', 4, 4'-benzophenone tetracarboxylic dianhydride (BTDE) and aromatic diamines with different chain flexibility and conformation symmetry.