As a special engineering material, polyimide has the advantages of high temperature resistance, radiation resistance and high mechanical strength, and is used in films, coatings, fibers, aerospace, electronic and electrical industries, foam plastics and photoresists. 4,4'-Diaminodiphenyl ether is one of the main raw materials of Chemicalbook. At the same time, 4,4'-diaminodiphenyl ether can also be used in the production of cross-linking agents, and is widely used to replace benzidine with carcinogenic effect in the production of azo dyes and reactive dyes. Therefore, 4,4'-Diaminodiphenyl ether is an intermediate with high added value