Lightweight and recyclable hybrid multifunctional foam based cellulose fibers with excellent flame retardant, thermal, and acoustic insulation property

The development of eco-friendly and good-performance foam materials is essential for the environment and energy saving. Conventional inorganic and organic foams suffer from brittleness and contamination problems. Here, we report a facile and scalable hybrid strategy to prepare shape-stable cellulose-based multifunctional foam via physical cross-linking of PVA and stabilization of HGMs. The prepared foam exhibits ultra-low density (27.0 mg/cm3), enhanced flame-retardant performance (the PHRR decreased from 161.8 to 89.1 kW/m2, LOI value up to 26.2%), low thermal conductivity (48.2 mW/mK), good acoustic insulation property (NRC of 0.41), and good mechanical properties (with specific compressive modulus of 15.3 MPa cm3/g). Moreover, the foam can be recycled under simplified procedures. Our approach provides a novel alternative to the manufacture of low-cost, eco-friendly, and scalable foam materials. This multifunctional lightweight material is highly sought after for modern engineering construction applications.