Mussel-inspired biomimetic surface functionalization strategy for the preparation of flame retardant, UV-resistant and mechanical-enhanced lyocell fabrics

Inspired by mussel adhesion proteins, the in-situ self-polymerization of dopamine (DA) was performed to generate a secondary reaction platform on the surface of lyocell fabrics, then a novel flame retardant and UV-resistant functionalized coating was constructed by introducing hexachlorocyclotriphosphazene (HCCP) and polyethyleneimine (PEI). Thermogravimetric (TG) and combustion test results showed that the introduced P/N elements had significant positive effects on char formation ability and flame retardancy. In particular, the peak heat release rate (PHRR) and total heat release (THR) of the treated sample decreased by 89.55% and 89.51%, while the limiting oxygen index (LOI) value of the treated samples maintained above 33.2% after 20 laundering cycles (LCs). In addition, the ultraviolet protection factor (UPF) values of the treated samples were significantly increased from 9.31 of the control sample to 666.04, and the tensile strength and elongation at break were correspondingly increased by 6.51% and 9.57%. This work provided a general and advanced strategy for the preparation of high-performance textiles with integrated flame retardancy, UV-resistance and mechanical enhancement.