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Re-examination of the intumescence mechanism of ammonium polyphosphate/pentaerythritol/zeolite 4A fire-retarded formulation using advanced spectroscopic techniques
https://orcid.org/0009-0006-7727-6453
https://orcid.org/0000-0003-1536-2015
https://orcid.org/0000-0002-7113-1687
The mixture of ammonium polyphosphate and pentaerythritol is a very efficient intumescent system suitable for polyolefins, especially polypropylene. In this article, the intumescence mechanism of this intumescent system with and without zeolite 4A used as a synergy agent is revisited. The intumescent system was investigated in depth using continuous-wave electron paramagnetic resonance spectroscopy, solid-state nuclear magnetic resonance, and the advanced technique, namely hyperfine sublevel correlation pulsed electron paramagnetic resonance. It was observed that the char generated between 250°C and 350°C is made of polycyclic heterocyclic radicals with nitrogen atoms and that free radicals are mainly generated at these temperatures with a spin concentration relatively stable at least up to 500°C. Moreover, the presence of hydrogen, carbon, nitrogen, and phosphorus was clearly evidenced in the chemical environment of free electrons at 350°C (hyperfine sublevel correlation pulsed electron paramagnetic resonance). Besides, it was also evidenced that 4A totally collapses below 250°C. Contrary to previous works suggesting the presence of aluminosilicophosphate complexes, this work demonstrated that distinct alumino- and silicophosphate complexes are generated and protected the residue at high temperatures.
Re-examination of the intumescence mechanism of ammonium polyphosphate/pentaerythritol/zeolite 4A fire-retarded formulation using advanced spectroscopic techniques
https://orcid.org/0009-0006-7727-6453
https://orcid.org/0000-0003-1536-2015
https://orcid.org/0000-0002-7113-1687
The mixture of ammonium polyphosphate and pentaerythritol is a very efficient intumescent system suitable for polyolefins, especially polypropylene. In this article, the intumescence mechanism of this intumescent system with and without zeolite 4A used as a synergy agent is revisited. The intumescent system was investigated in depth using continuous-wave electron paramagnetic resonance spectroscopy, solid-state nuclear magnetic resonance, and the advanced technique, namely hyperfine sublevel correlation pulsed electron paramagnetic resonance. It was observed that the char generated between 250°C and 350°C is made of polycyclic heterocyclic radicals with nitrogen atoms and that free radicals are mainly generated at these temperatures with a spin concentration relatively stable at least up to 500°C. Moreover, the presence of hydrogen, carbon, nitrogen, and phosphorus was clearly evidenced in the chemical environment of free electrons at 350°C (hyperfine sublevel correlation pulsed electron paramagnetic resonance). Besides, it was also evidenced that 4A totally collapses below 250°C. Contrary to previous works suggesting the presence of aluminosilicophosphate complexes, this work demonstrated that distinct alumino- and silicophosphate complexes are generated and protected the residue at high temperatures.
Re-examination of the intumescence mechanism of ammonium polyphosphate/pentaerythritol/zeolite 4A fire-retarded formulation using advanced spectroscopic techniques
https://orcid.org/0009-0006-7727-6453
https://orcid.org/0000-0003-1536-2015
https://orcid.org/0000-0002-7113-1687
The mixture of ammonium polyphosphate and pentaerythritol is a very efficient intumescent system suitable for polyolefins, especially polypropylene. In this article, the intumescence mechanism of this intumescent system with and without zeolite 4A used as a synergy agent is revisited. The intumescent system was investigated in depth using continuous-wave electron paramagnetic resonance spectroscopy, solid-state nuclear magnetic resonance, and the advanced technique, namely hyperfine sublevel correlation pulsed electron paramagnetic resonance. It was observed that the char generated between 250°C and 350°C is made of polycyclic heterocyclic radicals with nitrogen atoms and that free radicals are mainly generated at these temperatures with a spin concentration relatively stable at least up to 500°C. Moreover, the presence of hydrogen, carbon, nitrogen, and phosphorus was clearly evidenced in the chemical environment of free electrons at 350°C (hyperfine sublevel correlation pulsed electron paramagnetic resonance). Besides, it was also evidenced that 4A totally collapses below 250°C. Contrary to previous works suggesting the presence of aluminosilicophosphate complexes, this work demonstrated that distinct alumino- and silicophosphate complexes are generated and protected the residue at high temperatures.
Re-examination of the intumescence mechanism of ammonium polyphosphate/pentaerythritol/zeolite 4A fire-retarded formulation using advanced spectroscopic techniques
Caron, Matthieu (author) / Ben Tayeb, Karima (author) / Bourbigot, Serge (author) / Fontaine, Gaëlle (author)
Journal of Fire Sciences ; 42 ; 405-438
2024-09-01
Article (Journal)
Electronic Resource
English
| British Library Online Contents | 1994
| British Library Online Contents | 2010