Preparation and flame retardancy of titanium carbide-manganese dioxide/thermoplastic polyurethane composites

Thermoplastic polyurethane elastomer (TPU) was equipped with excellent properties, which was widely used in various fields of industry and living. However, the application scope of TPU was limited because the material was a kind of organic polymer material with high inflammability. Moreover, a large amount of CO, CO2, NOx and other toxic asphyxiating gases were released during combustion. The design of MXene-based hybrid flame retardant based on layered titanium carbide (Ti3C2Tx) and manganese dioxide (MnO2) was proposed for preparation of MXene-based hybrid/TPU nanocomposites. The mechanisms of flame retardancy, smoke suppression and toxicity reduction of the TPU composites were studied by means of TGA, XRD, SEM and other techniques. In the case of Ti3C2Tx-MnO2/TPU systems, adding 2.0wt% Ti3C2Tx-MnO2 hybrid results in the best flame retardant property among TPU nanocomposites. For instance, the total heat release (THR), the total smoke release (TSR), the total CO yield (CO TY) and the total CO2 yield (CO2 TY) are decreased by 28.62%, 27.79%, 34.12% and 23.25% respectively compared to TPU, besides 91.89% increase in residual char at 700℃. According to the analysis, Ti3C2Tx in MXene-based hybrid flame retardant is oxidized to TiO2 and co-catalyzed with MnO2 to form carbon, which not only improve the continuity and compactness of carbon layer after combustion of nanocomposite materials, but also block the entry of heat and oxygen and inhibit the release of flue gas.