Polymerized hierarchical vertical lamellar aluminophosphate as ecofriendly inorganic flame retardant for highly smoke-suppression bamboo scrimber

Due to its flammability, bamboo is gradually becoming incapable of meeting the increasing demand for building decoration materials. In this work, we utilized in-situ synthesis to prepare aluminophosphate (AP) modified bamboo bundles and bamboo scrimber (BS) with high flame retardance and smoke-suppression performance. Benefiting from the in-situ synthesis method, the high yield of hierarchical vertical lamellar AP forms a flower-like nanostructure and contributes to an organic-inorganic components in bamboo by binding metal ions and phosphate radical to carbohydrates, leading to an effective improvement in flame retardant properties. Under the optimized hydrothermal process, aluminophosphate bamboo scrimber (APBS) had a higher limiting oxygen index (LOI) (41.5 ± 0.5 %). The Cone calorimeter tests indicated that the APBS had reduced peak heat release rate (pHRR), total heat release (THR), peak smoke production rate (pSPR), total smoke release (TSR), CO production, and CO 2 production than the control sample. During the combustion process, AP forms a dense and stable flame-retardant layer on the surface of bamboo, effectively preventing the fibers from coming into contact with oxygen and reducing the release of volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Meanwhile, the Lewis acidity of AP can catalyze the dehydration and carbonization of cellulose in bamboo at lower temperatures, leading to the formation of a continuous and stable carbon layer. This study presents a sustainable, simple, and environmentally friendly approach to prepare AP materials that serve as effective flame retardants and smoke suppressants, thereby eliminating fire hazards associated with bamboo or other cellulosic materials. • Mesoporous AP structure uniformly and densely distributes in bamboo. • Highly efficient optimization for the application of bamboo scrimber is proposed. • Mechanisms of multi-effect of flame retardany of bamboo scrimber is revealed. • AP forms an inorganic layer to improve flame resistance and smoke suppression properties of bamboo scrimber.