Analysis of P-FR effects on cotton pyrolysis

New experimental method to analyse gases emitted in pyrolysis of textiles with/without phosphorus PIN FRs. Neat cotton (plain weave 170 g/m²) was compared to the same with 16.3% weight DOPO coating (9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide). The novel experimental method achieved steady-state pyrolysis of a small spot of textile, under argon, at temperatures 200°C – 700°C, by continuously moving fresh textile into this area. Emitted gas molecules were analysed using electron impact mass spectrometry. The DOPO reduced the cotton peak heat release rate by around 15% and increased LOI (limiting oxygen index) from 18.6% to 22.5%. Results show release of the radical scavenger PO from the DOPO-cotton from 480°C, as well as HOPO and HOPO₂ at lower temperatures than reported in literature using other materials/methods. DOPO-cotton showed reduced pyrolysis emissions of acetic acid and acrolein at lower temperatures than pristine cotton, but increased emissions of propene and larger molecules such as furfural.

“In-situ Detection of Phosphorus-Containing Gas Phase Species at Steady-State Pyrolysis of Flame Retardant Coated Cotton”. N. Tomasik, R. Otto, T. Mayer-Gall, B. Atakan, J. Analytical and Applied Pyrolysis, Journal, in press 2025, https://doi.org/10.1016/j.jaap.2025.107371