Synthesis and application of silicone modified flame retardant for polyester fabric

The flame-retardant treatment of polyester fabrics has been widely reported, but most of these treatments cause a significant decrease in the fabric’s handle, such as fluffiness and softness. This study designed and synthesised a new phosphorus-nitrogen-containing silicone oil (PNSO). Then, PNSO as a flame-retardant was treated on polyester fabric through a pad-dry-cure procedure. The limiting oxygen index (LOI), afterflame time and damaged length of the finished polyester fabric (PNSO-F) were enhanced from 20.5%, 73.1 s and 26.8 cm to 28.3%, 4.5 s and 12.3 cm, respectively. After 12 washes, PNSO-F retained its good flame-retardancy and anti-dripping properties. Furthermore, the flame-retardant mechanism of PNSO on fabric was investigated using different spectral methods , which revealed that nitrogen acting in the gas phase, and phosphorus and silicone in the condensed phase worked together to produce a synergistic flame-retardant effect. In addition, KES tests indicated that the fluffiness and softness of PNSO-F were significantly improved.