One-step and multi-functional polyester/cotton fabrics with phosphorylation chitosan: Its flame retardancy, anti-bacteria, hydrophobicity, and flame-retardant mechanism

Multi-functional polyester/cotton fabrics (T/C) have been synthesized through an environmentally benign process employing chitosan (CS), phosphoric acid, and urea as primary constituents to develop the coating (PCSU) with inherent flame retardancy and antibacterial properties. Subsequent hydrophobic modification was achieved through sequential deposition of SiO 2 and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS-17), establishing a rough surface architecture. This integrated fabrication strategy successfully combines multiple functional characteristics while maintaining process efficiency and demonstrating zero-waste generation throughout the treatment protocol. T/C-PCSU passes the vertical burning test and the limited oxygen index value reaches up to 30 %, after spraying the SiO 2 /FAS-17 (0.7 wt%), T/C-PCSU/F can retain wonderful flame-retardancy. After all, the peak heat release rate of T/C-PCSU/F presented a 42 % reduction compared with that of T/C. The analysis of char residues and volatiles demonstrates that the flame-retardant coating can form densely cross-linked char residues containing phosphorus, nitrogen, and silicon elements on the T/C surface. Flame-retardant coatings have a greater impact on cotton, thereby improving the flame retardancy of polyester components. Fortunately, the tensile strength of T/C-PCSU/F has been improved compared to that of T/C, but the air permeability has slightly decreased. In addition, T/C-PCSU/F has a high antibacterial rate against E. coli and S. aureus of 99.99 %, and under extremely low conditions of hydrophobic coating weight gain, its water contact angle data can reach 142°.