Self-Healing of Electrical/Mechanical Damage in Smart Copolyimide

Abstract

Polyimide (PI) dielectric films have been widely used in electronic equipment and power systems due to their chemical stability, high temperature resistance and excellent insulation strength. Meanwhile, electrical/mechanical damage is one of the main factors threatening reliability and service life, which could be solved with self-healing polyimides. However, the ultra-high stability of polyimide brings great difficulties to self-healing. In this work, a copolyimide (CPI) film copolymerized with polyurea (PUA) are designed to adapt to self-healing after electrical and mechanical damage. The key of this technology is that the PI unit can ensure the thermal stability and insulation strength of CPI, and the hydrogen bond in PUA can promote the self-healing of CPI after damage. Clearly, the CPI film prepared by simple copolymerization process has high mechanical properties and insulation strength, and also has good self-healing ability after mechanical and electrical damage. Furthermore, this method of preparing high strength, high insulation and self-healing CPI provides ideas for the development of smart PI, which will promote the application of intelligent PIs in the field of electrical and electronic engineering.