Products are based on thermoplastic polyimide resins or thermoset bismaleimide (BMI) resins. Aromatic polyimides are among the most thermally-stable organic materials. DuPontâs Kapton® film materials are an example of thermoplastic polyimide. Polyimide thermoplastics and BMI thermoset resins have high temperature resistance. Bismaleimide (BMI) resins have processing characteristics similar to epoxy resins and are used as laminating resins, prepregs, and adhesives.