Fabricating of flame retardant and antibacterial lyocell fabric based on thiamine pyrophosphate modification

To improve the flame retardant and antibacterial properties of lyocell samples, thiamine pyrophosphate (TPP), a kind of water-soluble vitamin derivative, was selected for the modification of lyocell fabric. Vertical burning test showed that the combustion of treated lyocell fabric was greatly reduced. The thermal stability and char-forming ability of the treated lyocell fabric were significantly improved whether in air or nitrogen atmosphere. The char residue of flame retardant lyocell sample was significantly increased from 4.9 wt% of the control sample to 25.9 wt% in air atmosphere, and Raman spectroscopy confirmed the formation of graphitic carbon. The total heat release (THR) and peak heat release rate (PHRR) of the treated lyocell fabric decreased by 80.4% and 90.4%. In addition, the limiting oxygen index (LOI) values of the washed samples increased from 18.0% of the original sample to 28.3% even after 40 laundering cycles (LCs), demonstrating excellent durable flame retardancy. The flame retardant mechanism was explored by thermogravimetry-Fourier transform infrared spectrometry (TG-IR), thermogravimetry-mass spectrometry (TG-MS) and Raman spectroscopy. Furthermore, the treated lyocell sample had good antibacterial performance to E . coli and S . aureus. This research indicates that TPP is an effective and potential intumescent flame retardant and antibacterial agent, which simultaneously endows lyocell fabric with multifunctional properties.