Flame-retardant composite coatings for cotton fabrics fabricated by using oxygen plasma-induced polymerization of vinyl phosphonic acid/cyclotetrasiloxane

Environment-friendly flame-retardant cotton textiles have been receiving considerable interest both in academic and industrial circles for years. Herein, a novel flame-retardant coating for cotton fabrics was reported based on vinyl phosphonic acid and 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane through an O-2 plasma-induced polymerization process. The coating on cotton fabrics was confirmed by Fourier transform infrared spectrophotometry, scanning electron microscopy and energy dispersive X-ray spectrometry. Excellent flame retardancy and thermal stability properties were found from thermogravimetric analysis, the limiting oxygen index, modified vertical burning tests and pyrolysis combustion flow calorimetry. The results revealed that there was a good synergistic effect between poly(vinyl phosphonic acid) and polysiloxane segments in flame-retardant cotton fibers. The new flame-retardant coating induced an earlier decomposition of cellulose, and enhanced the formation of stable char under thermal oxygen and significantly reduced the heat release capacity.