Cellulose–Chitosan Biodegradable Materials for Insulating Applications

Bio-based lightweight porous materials have attracted attention due to their unique properties and have become an interesting alternative to petroleum-based foams such as expanded polystyrene (EPS) and polyurethane foams. In this work, biodegradable cellulose pulp–chitosan foams were obtained through a low-cost, simple, and scalable method. A full factorial design was carried out to study the effects of three experimental factors (chitosan content, foaming agent concentration, and foaming time) on apparent density and mechanical properties. The prepared foams displayed low apparent densities (0.06–0.12 g/cm3), good mechanical performance (elastic modulus: 0.18–1.20 MPa, compressive strength: 0.02–0.11 MPa), excellent thermal insulation properties (thermal conductivities: 0.03–0.04 W/mK), and high biodegradation rates. The increase of chitosan content improved the water resistance and mechanical strength. Finally, these materials could be suitable for several applications in which thermal insulation, mechanical resistance, and water stability are crucial, including packaging and construction, as an alternative to traditional nonbiodegradable materials.