High-strength polyimide nano fiber porous membrane, and preparation method and application thereof

The invention discloses a high-strength polyimide nano fiber porous membrane. The porosity of the polyimide nano fiber porous membrane is 70-85%, the average pore diameter is 100-250 nm, the glass transition temperature is 260-400 DEG C, the tensile strength is 8-70 MPa, and the dimensional shrinkage after high-temperature 200 DEG C heat treatment for 1 hour is less than 0.3%. The chemical composition of the polyimide nano fiber porous membrane is copolymerized polyimide or blended polyimide. The invention also discloses a preparation method and application of the polyimide nano fiber porous membrane. The polyimide nano fibrous membrane disclosed by the invention is a membrane material having the advantages of high strength, low dimensional change rate, high porosity and favorable thermal properties.