Flame retardant and hydrophobic cotton using a unique phosphorus-nitrogen-silicon-containing coating

Phosphorus-nitrogen-silicon-containing coatings consisting of tris(hydroxymethyl)phosphine oxide (THPO), 3,5-diamino-1,2,4-triazole (guanazole), and polydimethylsiloxane (PDMS) were prepared via a simple spraying deposition technique and applied to the cotton fabric to impart flame retardancy and hydrophobicity. SEM image reveals that THPO/Guanazole/PDMS-coated fabric has a rough surface and XPS spectra confirm the composition of the coating on the cotton surface. Direct flame testing indicates that the as-prepared coating can protect the cotton from burning. The limiting oxygen index increased from 18.0% for the uncoated fabric to 32.0% for the THPO/Guanazole-treated sample and 27.0% for the THPO/Guanazole/PDMS-treated sample. Furthermore, with additional THPO/Guanazole, there was a gradual reduction in PHRR values, 60% (79.0 kW/m(2)) for C2 and 76% (48.2 kW/m(2)) for C3 lower than that of untreated cotton. After hydrophobic treatment of C2 with PDMS, the PHRR is reduced to 127.5 kW/m(2) (35.5% for C2-PDMS). Additionally, the coated cotton displays impressive hydrophobicity with a water contact angle of 133 degrees. This unique approach provides a facile and effective flame retardant and hydrophobic treatment for cotton fabric.

Automated summary

Phosphorus-nitrogen-silicon-containing coatings prepared by spraying deposition technique can impart flame retardancy and hydrophobicity to cotton fabric, increase the limiting oxygen index, reduce the combustion rate and heat release rate, and exhibit excellent hydrophobicity.