Construction of fully bio‐based flame retardant and antibacterial coating on polyester fabric with chitosan and ammonium phytate

Abstract In this work, a flame retardant and antibacterial coating was constructed on the surface of polyester (PET) fabric by a simple layer‐by‐layer self‐assembly method based on chitosan (CS) and ammonium phytate (APA). The introduction of the coating significantly improved the flame retardant, anti‐dripping, and antibacterial properties of PET fabrics. The PET fabric that has been treated exhibits a limiting oxygen index of 34.6%. During the vertical flame test, it forms an expanded char layer, reduces the damage length to 3.4 cm, and produces no molten drops. The cone calorimeter test results revealed that the peak heat release rate of the treated PET fabric decreased by 62.0%. Additionally, the finished PET fabric has significant antibacterial properties against Escherichia coli , a slight increase in tensile breaking strength, and a slight decrease in whiteness index. This study presents a fully bio‐based, simple, and effective method for flame retardant, anti‐dripping, and antibacterial finishing of PET fabrics.