Cleaner production to a multifunctional polyurethane sponge with high fire safety and low toxicity release

Conductive polymer composites have been caught increasing attentions in electromagnetic interference (EMI) shielding field. Due to the flammability of polymer and long-term high power working status, fire incidents on environment and human health must be taken into consideration during the preparation of the polymer mate-rials. Thus, developing an EM waves-clean material with exceptional fire safety and smoke suppression capacity is the vital issue. In this article, a facile and eco-friendly approach to fabricate flame retardant polyurethane (PU) sponge was carried out by layer-by-layer (LBL) self-assembly with octaammonium-polyhedral oligomeric sil-sesquioxane (OAPOSS) and titanium carbide (Ti3C2Tx) nanosheets. With the help of silicane and the barrier effect from Ti3C2Tx, the peak heat release rate (pHRR) and total heat release (THR) decreased by 50%. Thanks to the exceeding catalytic capacity of Ti3C2Tx nanoflakes, the production of harmful smokes or gases such as carbon oxide (CO) and carbon dioxide (CO2) were sharply reduced with 71% and 27%, respectively. Furthermore, the flame retardant PU sponge obtained electromagnetic interference (EMI) shielding capacity after dip-coating procedure in MXene dispersion owing to the excellent electrical conductivity of Ti3C2Tx nanosheets. The EMI shielding effectiveness (EMI SE) accomplished 32.57 dB and still remained 27.63 dB after 300 times compression. Therefore, this work could provide a promising way to accomplish flame retardant PU sponge with superior smoke suppression capacity, which could be used in cleaner production of modern electronics and EMI shielding materials.