Interface assembly of flower-like Ni-MOF functional MXene towards the fire safety of thermoplastic polyurethanes

In this study, three-dimensional flower-like Ni-MOFs were fabricated and successfully functionalized on multi-terminal lamellar MXene (Ti 3 C 2 T x ) by solvothermal method, and their flame retardant application in thermoplastic polyurethanes (TPU) was investigated. As expected, the addition of Ni-MOF@Ti 3 C 2 T x can improve the flame retardancy and smoke suppression properties of TPU. The heat release rate, the smoke release rate, total smoke production, CO and CO 2 release of the composite with only 1wt%MOF@Ti 3 C 2 T x were significantly reduced by 15%, 44%, 26%, 18%, and 8%, respectively. Furthermore, the carbon residues of TPU/Ni-MOF@Ti 3 C 2 T x composites were about 2-5 times that of pure TPU, indicating that the Ni-MOF@Ti 3 C 2 T x can inhibit the thermal degradation of TPU. The mechanism illustrated that the excellent fire safety properties of TPU/Ni-MOF@Ti 3 C 2 T x composites are due to the physical barrier, catalytical carbonization, and gas-phase flame retardant of Ni-MOF@Ti 3 C 2 T x . In this work, the dispersity, thermal stability, and flame retardancy of MXene were improved due to the modification of MXene with Ni-MOF by chemical bonding and physical adsorption, which can broaden the range of applications of MOFs.