Diethylene triamine penta methylene phosphonic acid encountered silver ions: a convenient method for preparation of flame retardant and antibacterial lyocell fabric

Ammonium salt of diethylene triamine penta methylene phosphonic acid (ADTPMPA), a novel flame retardant, was synthesized and grafted on the lyocell fabric to obtain a kind of flame retardant lyocell fabric (FR-lyocell). Then FR-lyocell was coated by Ag nanoparticles (Ag NPs) to fabricate flame retardant and antibacterial lyocell fabric (FR-Ag-lyocell). The elemental composition, surface morphology, combustion behavior and antibacterial activity of the lyocell fabric before and after modification were investigated. The flame retardant and antibacterial mechanism of FR-Ag-lyocell fabric was also analyzed. The limiting oxygen index (LOI) values of FR-Ag-lyocell fabric before and after 20 laundering cycles (LCs) reached 44.8% and 31.3%, respectively. The treated lyocell fabric possessed lower peak of heat release rate (pHRR) and total heat release (THR) values compared with control lyocell fabric. The FR-Ag-lyocell fabric exhibited excellent antimicrobial ability against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ), even after 10 LCs. These results indicated that FR-Ag-lyocell fabric had durable flame retardant and antibacterial properties. Graphic abstract