4,4-prime,5,5-prime Dioxydiphthalic dianhydride, a new polyimide monomer

4,4-prime,5,5-prime Dioxydiphthalic dianhydride (DODA), a new monomer for the synthesis of polyimide resins, was prepared by the action of a base on a 4,5-dihalophthalic anhydride in a polar aprotic solvent. Both potassium carbonate and a combination of potassium fluoride and water have afforded DODA in a high-yielding single-step reaction. The product was purified by crystallization of its di-n-butyl ester. A variety of polyimides and copolyimides incorporating DODA were prepared, and afforded creasable films having good physical properties. (Author)