Creating MXene/reduced graphene oxide hybrid towards highly fire safe thermoplastic polyurethane nanocomposites

Developing highly effective flame retardant polymeric materials with the release of low toxic fumes during burning still keep a huge challenge. In this work, we demonstrated successful synthesis of titanium carbide-reduced graphene oxide (Ti3C2Tx-rGO) hybrid via hydrogen bonding induced assembly of Ti3C2Tx and rGO, which was utilized to improve the thermal and fire safe performances of thermoplastic polyurethane elastomer (TPU). The results indicated that the Ti3C2Tx-rGO hybrid showed a strong adhesion and good compatibility with TPU host. Furthermore, as-prepared Ti3C2Tx-rGO hybrid was homogeneously dispersed in the TPU matrix due to the mutual intercalation of rGO and Ti3C2Tx preventing the re-aggregation. The thermal stability of TPU was dramatically improved after the introduction of Ti3C2Tx-rGO. With addition of 2.0 wt% Ti3C2Tx-rGO, the peak of smoke production rate and total smoke release of TPU nanocomposite were remarkably decreased by 81.2% and 54.0%, respectively. In addition, the TPU/Ti3C2Tx-rGO-2.0 showed distinct reductions in the peak of carbon monoxide production rate (54.1%) and total carbon monoxide yield (46.2%). The physical barrier effect, the catalytic charring of Ti3C2Tx-rGO hybrid and the chemical transformation of Ti3C2Tx were responsible for the excellent fire resistance of TPU/Ti3C2Tx-rGO systems. This work provides a novel strategy to significantly reduce the fire hazards of TPU, thus broadening its industrial applications.