Researchers found that phosphorous-modified cotton fabrics exhibit significantly enhanced thermal stability and flame-retardant properties, with a much higher char residue compared to untreated cotton.

A novel hyperbranched phosphorous containing poly(amidoamine-organosilicon) (P@PAMAMOSi) was successfully synthesized and the structure was characterized by fourier transform infrared spectra (FT-IR) and NMR. The cotton fabrics were wrapped with P@PAMAMOSi by sol-gel method. The P@PAMAMOSi modified cotton fabrics were proven by FT-IR and scanning electron microscopy (SEM). The thermal stability and combustion properties of the blank cotton and treated cotton fabrics were explored by thermogravimetric analysis (TGA), limiting oxygen index (LOI), vertical flammability, and cone calorimetry.

The data of TGA indicated that modified cotton fabrics have exquisite thermal stability, when the temperature reached 700 ¡ãC, the char residues of A30 treated cotton, B30 treated cotton, and C30 treated cotton were 29.5, 34.5, and 28.8 %, respectively; which is better than the 12.7 % of blank cotton. The results were verified by the LOI and combustion tests of cotton fabrics. The flame-retardant mechanism of treated cotton fabrics was analyzed by the FT-IR, X-ray photoelectron spectrometry (XPS), SEM, and energy dispersive X-ray spectroscopy (EDS), the treated cotton fabrics showed condensation phase and gas phase flame retardant mechanism. In addition, treated cotton fabrics showed desirable physical properties and mechanical properties.

Source: Progress in Organic Coatings Volume 188, March 2024, 108188