An efficient approach to fabricate lightweight polyimide/aramid sponge with excellent heat insulation and sound absorption performance

[Display omitted] •The polyimide fibre-based composite sponge was manufactured by foam forming.•The manufacturing process is simple, time-saving, high-efficiency, and low environmental pollution.•Polyimide fibre-based composite sponge has light weight, heat insulation, sound absorption and excellent compression-resilience property. Polyimide sponges have bright prospects in the weight reduction, heat insulation, and sound absorption equipment of aerospace, navigation, and other area due to their unique three-dimensional cellular structure and outstanding comprehensive performance. However, most polyimide sponges suffered from long and complex fabrication processes. Herein, an efficient and scalable approach, i.e. water-based foam forming, was proposed to fabricate ultralight and porous polyimide/aramid sponges (PASG). Attributed to the bubble-template nature of foam-forming, PASGs exhibit high porosity (>99%) and ultra-low density (∼10 mg/cm3), and possess excellent thermal and sound insulation performance with an optimum thermal conductivity of 34.89 mW/m·K and noise reduction coefficient of 0.41. Besides, PASGs demonstrate outstanding mechanical properties after 500 compression cycles. This strategy providing more possibilities for developing the next generation of high-performance thermal insulation and noise reduction materials.