Short‐cut polyisophthaloyl metaphenylene diamine fiber reinforced polyimide aerogel composites for improving thermal insulation and mechanical performance

Abstract Polyimide aerogels are often constrained by the poor mechanical performance when used as thermal insulation. In addition, there is requirement for flame retardant performance in the practical use. In this paper, a fiber‐reinforced polyimide aerogel material was prepared by compounding polyisophthaloyl metaphenylene diamine fibers with the aerogel, which present good thermal insulation and excellent mechanical properties, flame retardancy, thermal stability, and certain hydrophobicity, as well as being very lightweight. The compressive strength of the polyimide aerogel was increased from 0.34 to 0.58 MPa by using the fibers as the reinforcing phase; meanwhile, the flame‐retardant property was improved, and the limit oxygen index was increased from 33.8 to 36.5. The composite aerogel material has good potential for application in the fields of thermal insulation, building insulation, aerospace, etc.