Polyimider

Polyimider is not a standard term in polymer science. In most contexts, the correct term for polymers containing imide linkages is polyimide. When the word polyimider appears, it is often a misspelling or informal usage and may refer to a person or organization involved in polyimide research and production, or less commonly to a material described nontraditionally as a polyimide-like polymer.

Polyimides are a family of high-temperature polymers characterized by imide linkages in their backbone. They are typically formed by the condensation or polyaddition of a dianhydride with a diamine, followed by an imidization step to establish the imide rings. Variants use different dianhydrides and diamines to tailor properties such as thermal stability, flexibility, and solubility. Common examples include materials derived from pyromellitic dianhydride and oxydianiline, and commercially well-known polyimides used in films and coatings.

Key properties of polyimides include high thermal stability, with glass transition temperatures often well above 200°C and decomposition temperatures that remain high in inert environments. They exhibit good mechanical strength, chemical resistance, and excellent dielectric properties, making them suitable for electronics, aerospace, and high-performance coatings. Processing can be challenging due to limited solubility and high melt viscosity, though soluble or semi-crystalline variants have been developed to broaden fabrication options.

Applications span insulating films (such as Kapton), flexible circuitry, advanced coatings, and structural components in demanding environments. The term polyimide remains the established descriptor; “polyimider” may arise from nonstandard usage and should be clarified in context. See also polyimide for a broader overview.