One-pot green synthesis of polybenzoxazine-based aerogels for intrinsically hydrophobic thermal insulation

Polybenzoxazine (PBz) aerogels are promising candidates for high-performance thermal insulation due to their lightweight nature and excellent thermal stability. However, the preparation of non-green solvents and their non-hydrophobic nature result in poor thermal insulation properties during application, which seriously hinders the development of PBz aerogels. Herein, we report a green, one-pot strategy to fabricate a novel polybenzoxazine-based (BPBz/SiO₂) hybrid aerogels with inherent hydrophobicity by incorporating boric acid and methyltrimethoxysilane. The prepared aerogels exhibit low density (0.144 g·cm⁻³), low thermal conductivity (0.0355 W·m⁻¹·K⁻¹), and excellent fire resistance. Remarkably, the BPBz/SiO₂ hybrid aerogels exhibit outstanding intrinsic hydrophobicity (a water contact angle of 144°) and effectively prevent the adhesion of contaminants on the surface. This work is expected to play a significant role in advancing green synthesis technologies, innovating aerogel structural design, and developing high-performance thermal insulation materials.