Recyclability and Self-Healing of Dynamic Cross-Linked Polyimide with Mechanical/Electrical Damage

Recyclability and self-healing are two most critical factors in developing sustainable polymers to deal with environmental pollution and resource waste. In this work, a dynamic cross-linked polyimide insulation film with full closed-loop recyclability is successfully prepared, which also possesses good self-healing ability after being mechanical/electrical damaged depending on the Schiff base dynamic covalent bonds. The recycled and self-healed polyimide film still maintain its good tensile strength (σ_t) >60 MPa with Young's modulus (E) >4 GPa, high thermal stability with glass transition temperature (T_g) >220 °C, and outstanding insulation property with breakdown strength (E₀) >358 kV mm⁻¹, making it a very promising low energy consumption and high temperature resistant insulation material. The strategy of using Schiff base dynamic covalent bonds for reversible repairing the structure of high T_g polyimides promotes the wider application of such sustainable and recyclable material in the field of electrical power and micro-electronics.