A sustainable approach to enhance flame retardant, antibacterial and UV resistance of lyocell fabrics treated with luffa phosphate derivatives and emodin

A multifunctional lyocell fabric with flame retardant, antibacterial and ultraviolet (UV)-resistant properties was fabricated. First, a novel and efficient eco-friendly intumescent flame retardant was synthesized by using natural luffa as raw materials, and was applied to lyocell fabric to improve its flame retardancy. Then, the flame retardant lyocell fabric was treated by emodin to simultaneously obtain the antibacterial and UV-resistant properties. The surface morphology and chemical structure of the treated fabric were analyzed by scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, which confirmed the P-O-C covalent bond between the flame retardant and the fabric. Thermogravimetric, limiting oxygen index and cone calorimetry analysis demonstrated that the treated fabric possessed excellent char formation ability, thermal stability and flame retardancy. Thermogravimetric/infrared spectroscopy analyses of the treated fabric and the morphological study of the char residue after burning suggested that both gas-phase and condensed-phase mechanism contributed to the flame retardant improvement of lyocell fabric. In addition, after 20 laundering cycles, the treated fabric still maintained excellent flame retardant, antibacterial activity, and UV resistance properties. This study provided an eco-friendly and facile approach to produce lyocell fabric with multifunction of flame retardant, antibacterial and UV resistance.