Chemically crosslinked carboxyl-containing polyimide hydrogen separation membrane and preparation method thereof

The invention provides a chemically crosslinked carboxyl-containing polyimide hydrogen separation membrane and a preparation method thereof. A copolyimide is prepared from dianhydride and diamine according to the molar ratio of 1: 1 through condensation polymerization and chemical imidization reaction, and respectively selects dianhydride A, rigid diamine and carboxyl-containing diamine C. Chemical crosslinking is performed on polyimide through glycidyl ether, so that the polyimide is crosslinked with carboxyl (chemically crosslinked polyimide with carboxyl: Polyimide, hereinafter referred to as PI molecular chain), and the permeability and selectivity of the membrane to hydrogen can be improved. The chemically crosslinked polyimide membrane material is easy to prepare, and the synthesized polyimide is large in free volume and has good air permeability and selectivity; and by using diamine containing carboxyl, polyimide can be crosslinked, the molecular free volume can be increased while the molecular chain m