▎ 摘　　要

NOVELTY - Preparing functionalized cross-linked polyimide aerogel heat insulation material comprises (i) adding cross-linking agent into container, adding nitric acid, water bath stirring, filtering when it is hot, precipitating, adding the precipitate in a vacuum drying box in vacuum drying to obtain the oxidation-modified cross-linking agent, (ii) taking diamine in the beaker, adding NMP, stirring to completely dissolve, adding dianhydride, stirring to obtain suspension, taking amide modified cross-linking agent powder in the step (i) to disperse in NMP solution to obtain the mixed solution, ultrasonically processing by ultrasonic cell crusher, adding the suspension solution to stir uniformly, adding acetic anhydride and pyridine, stirring and allowing to stand to make the gel, (iii) aging the functionalized cross-linked polyimide gel obtained in the step (ii) with anhydrous ethanol solution with different volume fraction of NMP, and drying, and (iv) heating, and drying in vacuum drying box. USE - The functionalized cross-linked polyimide aerogel heat insulation material is useful in high-end thermal insulation materials and other fields. ADVANTAGE - The material: has excellent stability; density about 0.0520.078 g/cm3, and compressive strength 0.31.1Mpa, volume shrinkage rate about 7.22% 15.63%, and thermal conductivity is 0.01520.021 W/(m-K).