Eco-friendly in-situ mineralization of bamboo for flame retardancy

An inorganic-organic structure including calcium carbonate (CaCO3) and bamboo was prepared via in-situ mineralization to improve the flame retardant properties of bamboo. During the mineralization, CaCO3 deposited mostly in parenchyma cells with pits and multilayer cell walls, which contributed to a stable cross-linked structure in bamboo by binding negatively charged calcium ions to carboxyl groups. Also, mineralization reduced the relative content of carbohydrates but promoted the formation of char residue. Cone calorimetry tests demonstrated that the mineralized bamboo had substantially reduced peak heat release rate (pHRR), lower total heat release (THR), lower peak smoke produce rate (pSPR) and total smoke release (TSR) than control bamboo. The improved flame resistance and smoke suppression properties of bamboo were primarily attributed to the even and dense coverage of non-combustible CaCO3.