Polyimide aerogels have been cross-linked through multifunctional amines. This invention builds on “Polyimide Aerogels With Three-Dimensional Cross-Linked Structure,” (LEW-18486-1), NASA Tech Briefs, Vol. 34, No. 8 (August 2010), page 38, and may be considered as a continuation of that invention, which results in a polyimide aerogel with a flexible, formable form.
Gels formed from polyamic acid solutions, end-capped with anhydrides, and cross-linked with the multifunctional amines, are chemically imidized and dried using supercritical CO2 extraction to give aerogels having density around 0.1 to 0.3 g/cm3. The aerogels are 80 to 95% porous, and have high surface areas (200 to 600 m2/g) and low thermal conductivity (as low as 14 mW/m-K at room temperature). Notably, the crosslinked polyimide aerogels have higher modulus than polymerreinforced silica aerogels of similar density, and can be fabricated as both monoliths and thin films.
This work was done by Mary Ann Meador of Glenn Research Center and Haiquan Guo of Ohio Aerospace Institute.
Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steven Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. LEW-18864-1