Improving the hygroscopicity and flame retardancy of polyamide 6 fabrics by surface coating with β-FeOOH and sulfamic acid

A bio-based durable reactive flame retardant for cotton fabric based on lentinan

Cotton fabric has extensive application due to its comfort and breathability. However, the inherent flammability limits its wide application. Durable polysaccharide-based flame retardants with a low impact on the softness of fabrics are rarely reported. In this work, a novel flame retardant ammonium phosphate of lentinan (APLNT) was synthesized and grafted on the surface of cotton fabric. The treated cotton fabric had a high limiting oxygen index (LOI) value of 43.3 % and passed the vertical burning test (VBT) with a 21.1 % weight gain of APLNT. Compared with control cotton, the peak heat release rate and total heat release values of Cotton-APLNT2 decreased by 92.8 % and 50.9 %, respectively. In addition, the cotton fabric still passed the VBT and kept an LOI value of 27.0 % even after 50 laundering cycles, indicating that the fabric can be used for daily needs. More importantly, the treated fabric remains soft. This research provided a new strategy for preparing bio-based durable flame retardant cotton fabrics.

Preparation and application of halogen-free and efficient Si/P/N-containing flame retardants on cotton fabrics

Cotton fabric is extensively utilized due to its numerous applications, but the flammability associated with cotton fabric poses potential security risks to individuals. A halogen-free efficient flame retardant named poly [(tetramethylcyclosiloxyl spirocyclic pentaerythritol)-piperazin phosphate] (PCPNTSi) was developed to consolidate the fire retardance of cotton fabrics. After PCPNTSi treatment, the limiting oxygen index (LOI) of cotton fabric with 30 % weight gain (CP3) was raised to 32.8 %. In the vertical flammability test (VFT), CP3 has self-extinguished performance with a char length of 8.7 cm. The heat release rate (HRR) of cotton fabric with 20 % weight gain (CP2) is 78.8 % lower than that of pure cotton fabric (CP0). In addition, the total smoke release (TSP) of CP2 is 41.7 % lower than that of CP0, indicating PCPNTSi gives cotton fabric a good capability to inhibit smoke release. Finally, the possible flame retardant mechanism was discussed by the data of scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), Fourier Transform infrared spectroscopy (FT-IR) and thermogravimetric infrared spectroscopy (TG-IR). The results show that PCPNTSi is an intumescent flame retardant acting in both gas phase and solid phase.