High-performance Polyimide/Polypyrrole-CNTs@PEG composites for integrated thermal management and enhanced electromagnetic wave absorption

Given the inevitable generation of electromagnetic radiation within electronic devices, accompanied by heat, and the detrimental effects of such radiation on the performance of precision instruments, the development of materials that integrate microwave absorption with thermal energy storage has become imperative. In this study, a novel polyimide/polypyrrole carbon nanotube (PI/PPy-CNTs) porous structure was fabricated using a template method, freeze-drying, and carbonization processes. Subsequently, polyethylene glycol (PEG) was encapsulated within this structure via vacuum impregnation to produce PI/PPy-CNTs@PEG phase change composites (PCPCCs). Multi-interface heterostructures are designed at the micro level to improve dielectric loss and thus enhance electromagnetic wave absorption (EWA) performance, and dense networks are constructed at the macro scale to improve thermal conductivity. The resulting sample exhibited a thermal conductivity of 0.72 W/(m·K), a photothermal conversion efficiency of 92.9%, an enthalpy value of 148.2 J/g, and a minimum reflection loss of − 42 dB. Compared to pure PEG, the thermal conductivity of the composite increased by a factor of 2.3. In conclusion, these multifunctional PCPCCs show significant potential for applications requiring integrated thermal management and advanced EWA performance.