Polyetherimide Material

Polyetherimide (PEI), also known as polybisphenol A tetraphthalimide, is produced through the condensation polymerization of bisphenol A dianhydride with various aromatic diamines (such as m-phenylenediamine) and an appropriate amount of telomerizing agents (aniline, phthalic anhydride, etc.) in a polar solvent at high temperatures. It appears as a transparent amber color, is non-toxic and odorless, with a density of 1.27g/cm3 and a water absorption rate of 0.25% at 23℃ for 24 hours. Developed successfully by the American GE company in 1970, PEI achieved industrial production in 1982. PEI exhibits excellent high-temperature resistance, high strength, high modulus, and broad chemical resistance. Additionally, PEI possesses superior water resistance and resistance to boiling water decomposition. However, it can be dissolved in solvents such as toluene, trichloroethylene, and ammonium hydroxide at 150℃, and has poor alkali resistance.

The production process of PEI mainly includes three steps: monomer preparation, polycondensation synthesis, and processing and molding. The monomers of PEI include two types: dianhydrides and diamines. The polycondensation of PEI is mainly achieved through three methods: low-temperature polycondensation, high-temperature polycondensation, and melt polycondensation.

PEI finds widespread applications. In the aerospace sector, PEI resin and its composites are utilized in payload systems and electrical components within aircraft cabins. In the industrial machinery domain, PEI, due to its high temperature resistance and superior mechanical strength, serves as precision mechanical components demanding high temperature and strength, such as bearings, automotive heat exchangers, and carburetor housings. In the electronic and electrical domain, PEI, owing to its high strength and rigidity, is suitable for manufacturing optical fiber distribution boxes, waterproof sockets, and the like.