The invention relates to
polymer separation
membrane technology, in particular to a method for preparing a polyoxyethylene-introduced cross-linked modified
polyimide gas separation membrane. The method comprises the steps of: 1) performing a cross-linking reaction, namely dissolving
polyimide and a cross-linking agent, namely polyether amine into a
solvent respectively until a
polymer and the cross-linking agent are completely dissolved, mixing two solutions, and then stirring the obtained solution for 5 to 30h to react; and 2) preparing a homogeneous membrane, namely dumping the solution on a
polyethylene plate after a complete mixed reaction of the solution, performing
drying and film formation at the temperature of between 25 and 60 DEG C, placing the obtained homogeneous membrane into water for 1 to 5 days to remove the unreacted cross-linking agent in the homogeneous membrane, and then placing the membrane into a vacuum baking oven to bake at the temperature of between 50 and 120 DEG C for 5 to 24h, wherein the obtained
membrane thickness is between 50 and 150mu m. The method uses the special cross-linking agent, namely the polyether amine to perform comprehensive cross-linking modification on the
polyimide, and obtains the homogeneous membrane with excellent CO2
gas separation performance.