Despite the wide applications in clothing, furniture, and transportation, the well-known "scaffolding effect" in polyester-cotton fabric has caused significant fire hazards compared to sole polyester or cotton fabrics. Therefore, it is of practical significance to endow polyester-cotton fabric with excellent fire safety. In this work, an organic-inorganic composite coating comprising nitrogen-phosphorus-silicon-containing flame retardant and silver nanoparticle-loaded halloysite nanotubes (Ag@HNTs) was designed and prepared to improve the fire safety of polyester-cotton fabrics. Microscale combustion colorimeter results indicated that the peak heat release rate of the modified polyester-cotton fabric with such a composite coating was reduced by 47%. Meanwhile, it could self-extinguish in 9 s after being ignited, and the limiting oxygen index was up to 25%, indicating excellent fire safety. In addition, the total smoke release of the coated polyester-cotton fabric was reduced by 21%, illustrating that the coating of Ag@HNTs could eliminate the smoke generated. The treated fabric also exhibited superior water resistance. Flame retardant mechanisms were well investigated using thermogravimetric analysis-infrared spectrometry analysis and chemiluminescence by studying the gaseous degradation products and hydroxyl radical in the gas phase. This work provides an effective approach to fabricating high-performance flame retardant and smoke-suppressive coatings for textiles.
Keywords: chemiluminescence; flame retardant mechanism; halloysite nanotubes; polyester-cotton fabric; silver nanoparticles; washing resistance.