Superstrong Thermo‐Acoustic Insulating Polyethersulfone Aerogels Fabricated via Freeze Casting‐Etching‐Ambient Pressure Drying Strategy

ABSTRACT Thermo‐acoustic insulation aerogels have received increasing attention in the aerospace sector. However, fabricating superstrong thermo‐acoustic insulation aerogels via a green and efficient method remains a significant challenge. Herein, superstrong polyethersulfone (PES) aerogels are successfully fabricated via a novel and efficient strategy, integrating freeze casting, etching with water, and mild ambient pressure drying (APD), which involves no extra organic solvents. By tuning the PES concentration, PES aerogels with different morphologies and microstructures are tailored, enabling a tunable property spectrum to meet diverse application needs. Specifically, the 11 wt.% PES demonstrates an exceptional axial compression modulus (36.4 MPa), making it ideal for load‐bearing components in aerospace systems. In contrast, the 9 wt.% PES achieves an enhanced acoustic performance (NRC = 0.41), underscoring its potential for construction application. Besides, all PES aerogels maintain low thermal conductivity (0.0397–0.0569 W/(m·K) in the axial direction) and self‐extinguishing behavior. Notably, the PES aerogels are fully recyclable, which presents an opportunity to establish a sustainable circular economy. And last but not least, this fabrication strategy is universal and applicable to other engineering plastics. This work establishes a green, cost‐effective and scalable pathway to fabricate superstrong thermo‐acoustic insulating polymer aerogels, overcoming a key bottleneck toward their industrial adoption.