A novel triazine-based covalent organic framework: Enhancement fire resistance and mechanical performances of thermoplastic polyurethanes

In this study, we decided to synthesize a flame-retardant triazine-based covalent organic framework (FT-COF) via solvothermal reaction, to improve the fire safety and mechanical properties of thermoplastic polyurethane (TPU). By adding 3.0 wt% of FT-COF, the tensile strength and elongation of TPU increased by 69% and 12%, respectively. After incorporating of FT-COF nanoparticles, the thermal stability of TPU was significantly improved that resulted in the increasing of char residue up to 158% for TPU/FT-COF 3%. With addition of 3.0 wt % FT-COF, the peak heat release rate, total heat release of TPU composite were dramatically decreased by 51.6% and 47.3%, respectively. Besides, the TPU/FT-COF 3% indicated distinct reductions in the total smoke release (41.1%) and the peak of carbon monoxide production rate (43.53%). This study offers a new plan to outstandingly reducing the flammability of TPU, thus developing its industrial usage.