Objective Cotton fabrics are extensively utilized for their softness and wearing comfort, but the flammability is a significant drawback. Reports indicate that the human casualties and financial losses caused by fires related to cotton fabrics are unimaginably high every year. Therefore, it is crucial to improve the flame-retardancy of cotton fabrics. Unfortunately, the most widely used halogen-containing flame retardants face restrictions due to the production of halogenated hydrocarbons when burned. In addition, cotton fabrics with a single flame-retardant function are no longer sufficient to meet normal application needs, and customers demand that flame-retardant cotton fabrics would also possess functions such as waterproofing, antibacterial properties, and UV resistance. Consequently, the development of additives to enhance the flame retardancy and antibacterial functions for cotton fabrics is essential. Method γ-urea-propyltriethoxysilane (T E S P R) and phenylphosphonic acid (P P O A) were utilized in the preparation of flame-retardant cotton fabrics using the sol-gel technique. The flame-retardant cotton fabrics were subsequently analyzed using various techniques, including scanning electron microscopy, thermogravimetric analysis, vertical flame test, cone calorimetry test, antibacterial activities, universal material testing machine, and fabric air permeability testing. Results The results indicated that the T E S P R-P P O A coating was successfully deposited on the surface of cotton fabrics. The thermogravimetric analysis revealed that although the initial thermal degradation temperature of TESPR/PPOA flame retardant cotton fabrics was lower compared with that of cotton fabrics, the char residues in the high-temperature zone were increased. Moreover, TESPR/PPO A flame retardant cotton fabrics was able to succeed a rapid self-extinguishment after the igniter was r e m o v e d, with the afterflame time and the afterglow lime being reduced to 0 s. Meanwhile, the damaged length of TESPR/PPOA flame retardant cotton fabrics obtained from vertical flame test was 8. 1 cm, and the limiting oxygen index reached 27. 2%. Compared with that of cotton fabrics, the peak heat release rate value of TESPR/PPOA flame retardant cotton fabrics decreased from 124 kW/m 2 to 94 kW/m2, and the total heat release value decreased from 4. 1 MJ/m2 to 3. 6 MJ/m2. After the flame retardant treatment, smoke release was effectively mitigated. The total smoke production value of flame retardant fabrics was smaller than that of cotton fabrics. In addition, the antibacterial properties of T E S P R/P P O A flame retardant cotton fabrics against E. coli and S. aureus were 99. 8 3 % and 99. 2 8 %. However, the mechanical properties of the flame retardant cotton fabrics were deteriorated severely due to the acidity of P P O A. The warp breaking force decreased from about 308 N to 242 N in the warp directions, and the weft breaking force decreased from about 329 N to 272 N in the weft directions. Therefore, the breaking force of T E S P R/P P O A flame retardant cotton fabrics in the warp and weft directions was reduced by approximately 21. 4 3 % and 17. 3% respectively compared with that of cotton fabrics. Fortunately, compared with that of cotton fabrics, the air permeability of TESPR/PPOA flame retardant cotton fabrics decreased from about 7 0 8. 8 m m/s to 5 8 3. 8 m m/s, reduced by only about 1 7. 7 %. Therefore, TESPR/PPOA flame retardant cotton fabrics retained better air permeability compared with that of cotton fabrics. Conclusion The results presented above demonstrate that the deposition of TESPR/PPOA can endow better flame retardant effect and better antibacterial properties to cotton fabrics, while TESPR/PPOA flame retardant cotton fabrics maintain better air permeability compared with that of untreated cotton fabrics. Additionally, the TESPR/PPOA coating has a certain inhibitory effect on the peak heat release rate. However, it is worth noting that the mechanical properties of these flame retardant cotton fabrics experience a certain degree of reduction in tensile strength and the study did not investigate their wash durability. In future research, further optimization of the fabrication process is necessary to minimize the impact on the mechanical properties of the cotton fabrics, and it is also important to comprehensively explore the fabric characteristics such as water wash resistance to improve efficiency and broaden its potential applications in areas such as clothing, home furnishings, and decoration. © 2024 China Textile Engineering Society. All rights reserved.
