Flame Retardant Material Based on Cellulose Scaffold Mineralized by Calcium Carbonate

Abstract

Wood-based functional materials have developed rapidly. But the flammability significantly limits its further application. To improve the flame retardancy, the balsa wood was delignified by NaClO2 solution to create a cellulose scaffold, and then alternately immersed in CaCl2 ethanol solution and NaHCO3 aqueous solution under vacuum. The high porosity and wettability resulting from delignification benefited the following mineralization process, changing the thermal properties of balsa wood significantly. The organic-inorganic wood composite showed abundant CaCO3 spherical particles under scanning electron microscopy. The peak of the heat release rate of delignified balsa-CaCO3 was reduced by 33% compared to the native balsa, according to the cone calori-metric characterization. The flame test demonstrated that the mineralized wood was flame retardant and self-extinguish. Additionally, the mineralized wood also displayed lower thermal conductivity. This study developed a feasible way to fabricate a lightweight, fire-retardant, self-extinguishing, and heat-insulating wood composite, providing a promising route for the valuable application of cellulosic biomass.