Eco-Friendly Tourmaline@MOF Lignocellulose Aerogel with Favorable Fire Retardancy and Smoke Suppression for Insulation Materials

Inflammable insulation materials cause fire hazards, especially in smoke harm. High-performance flame-retardant insulation materials are urgently needed to address these safety issues. Herein, a multiple flame-retardant strategy was proposed to prepare a novel eco-friendly tourmaline/metal–organic framework (MOF) lignocellulose aerogel (TMLA) from deep eutectic solvent (DES)-treated low-value wood with favorable flame retardancy, smoke suppression, and thermal insulation by directional freeze-casting. The combination of DES treatment, tourmaline, and MOF synergistically promotes the flame retardancy of TMLA. In addition, the total smoke release is reduced due to the sedimentation of negative oxygen ions. Compared with the lignocellulose aerogel, the heat release rate, total heat release, and total smoke release of TMLA were reduced by 55.37, 52.37, and 64.20%, respectively, and the limiting oxygen index was greatly enhanced by 30.25%. The directional structure of TMLA results in anisotropy, leading to ideal axial thermal insulation properties (28.13 mW/mK) and a favorable compression strength (1.83 MPa). Supported by the positive outcomes of the life cycle assessment, the prepared TMLA is eco-friendly and has superior flame retardancy and smoke suppression to pave the way for the sustainable production and use of insulation materials.