Bis(4-aminophenyl) ether is a monomer used as a cross-linking agent. It is also used in the preparation of poly(imideurea)s, polyimide silica composite membrane, which finds application in gas separation techniques. It is utilized in products such as wire enamels, coatings, adhesives, insulating varnishes, coated fabrics, flame-retardant fibers, oil sealants and retainers. Further, it is used in the preparation of polymer films for electrolyte membranes. In addition to this, it is used as an insulation for cables and printed circuits, and laminates and composite for aerospace vehicles.