Amide acid oligomer process for molding polyimide composites

Abstract

An amide acid oligomer (AAO) solution, methods of making the same, powder, AAO solution prepregs, AAO dry prepreg, imide prepregs, and fiber reinforced polyimide composites with high temperature resistance and excellent mechanical properties are disclosed herein. In some embodiments, a method of making an AAO solution includes dissolving an aromatic diamine and an aromatic tetracarboxylic compound in a solvent to form a mixture, wherein the solvent has a boiling point of less than 150° C.; stirring the mixture at a temperature ranging from about 5° C. to about 60° C. for about I hour to about 24 hours to form a reaction solution; adding unsaturated acid anhydride to the reaction solution; and stirring the reaction solution at a temperature ranging from about 5° C. to about 60° C. for about 1 minute to about 180 minutes to form an amide acid oligomer solution, the amide acid oligomer solution having amide acid oligomer in the solvent.