Ball-Milled BN Nanodisks Loaded With LDH Nanosheets: Facilely Assembled Nanostructure Aiming for Suppression on Heat and Toxicant Emissions

The practical usage of thermoplastic polyurethane (TPU) has been significantly hindered by its well-known tendency to pose a high fire hazard due to the release of substantial heat and toxic volatiles. Here, a binary nanostructure of B-LDH-C based on boron nitride (BN) nanosheets and layered double hydroxide (LDH) was fabricated as a flame-retarded filler for TPU. Specifically, the addition of 3.0 wt% B-LDH-C, results in significant reductions of 44.7% in peak heat release rate, 14.6% in total heat release, and 56.5% in peak smoke production rate. In addition, the peak CO yield is reduced by 38.4%. These results indicate reduced fire toxicity. Moreover, the TG-IR test points out the marked hindrances in combustible (hydrocarbons, esters, etc) and toxic gases (aromatic compounds, HCN). The results collectively demonstrate the high effectiveness of B-LDH-C in improving the fire safety of TPU, which is pertaining to the dual roles of B-LDH-C. The research could inspire the facile fabrication of binary structures, enhancing their potential in polymer-matrix composites and other applications.