Polyimide (PI) is a high-performance organic polymer material containing imide ring (-CO-NR-CO-) structural units in its main chain. It is typically produced by the polycondensation reaction of aromatic dianhydrides and diamine monomers. Polyimide possesses excellent thermal and chemical stability, making it one of the engineering plastics with the best heat resistance. It maintains good mechanical and electrical insulation properties over a wide temperature range, thus finding widespread application in high-end materials.
Polyimide materials are generally classified into two main categories: thermosetting and thermoplastic. Depending on the molecular structure and processing method, it can be made into various forms such as films, fibers, foams, coatings, and composite materials. This type of material features high temperature resistance, radiation resistance, solvent resistance, low dielectric constant, and excellent dimensional stability, but it is difficult to process and has a high cost. Industrially, polyimide is often synthesized using a two-step method (polyamic acid method) or a one-step method to achieve control over molecular structure and properties.
Due to its excellent comprehensive properties, polyimide is widely used in fields such as electronic information, aerospace, microelectronic packaging, flexible displays, insulating materials, and high-temperature structural materials, making it one of the essential functional materials in modern high-tech industries. With the development of advanced manufacturing and electronic technology, the role of polyimide in high-frequency and high-speed electronic devices, flexible electronics, and extreme environment applications is becoming increasingly prominent, possessing significant scientific value and engineering significance.
