Polyimides (PI) are high-performance polymers of imide monomers which contain two acyl groups (C=O) bonded to nitrogen (N). These polymers are known for their high temperature performance in the 400-500°C range as well as chemical resistance. They are used to replace the conventional use of glass, metals and even steel in many industrial applications. Polyimides offer excellent mechanical properties and thus find use in applications that demand rugged organic materials, e.g. High temperature fuel cells Flat panel display Aerospace applications Chemical and environmental industries As well as various military applications