Polyimide aerogels have excellent thermal and mechanical properties, resulting in various applications, especially in insulation areas. However, the conventional methods for directly producing aerogel blocks can be time-consuming and expensive due to the long-term solvent exchange and drying. This study developed two alternative techniques, adding dimethyl sulfoxide solvent and epoxy into the polyimide aerogel particles and consolidating them to obtain PI aerogel blocks or stock shapes. This approach reduced the cycle time of the process by nearly 60% compared to the directly obtained stock shapes. Samples with epoxy look promising in appearance and mechanical properties compared to the stock shapes made directly. The compression test shows that adding epoxy improves the mechanical property and compressive strength at 10% strain by 18%. In the same context, the samples made using dimethyl sulfoxide as a solvent exhibit higher thermal stability and porosity when compared to directly made stock shapes. These techniques provide a range of good thermal and mechanical properties for polyimide aerogel stock shapes prepared from the particles.

It is noteworthy to mention that synthesizing the polyimide aerogel powder, which is carried out in this study, benefits from two advantages: (i) the powder particles can be used for some specific applications where the monolith is not suitable and (ii) there is a possibility to investigate how a polyimide aerogel monolith can be made through the polyimide powder to reduce its cost and cycle time. In this study, two straightforward methods, wet gel grinding and emulsion, are introduced to prepare polyimide aerogel powders using ambient pressure drying. The microscopic properties of interest, including skeletal and porous structures, microparticle size and assembly, combined with macroscopic properties such as thermal stabilities and conductivities (0.039 W/m·K), confirm that the fabricated microparticles with a size in the range of 7–20 μm and porosity in the range of 65–85% are thermally stable up to 500 °C.