Effect of phosphoric acid on chemical transformations during Nomex pyrolysis
The thermal degradation of Nomex [poly(m-phenylene isophthalamide)] impregnated with phosphoric acid has been investigated by the analysis of the corresponding pyrolysis products, which were fractionated into gases, liquids, and char. Gas chromatography (GC) and/or gas chromatography/mass spectromet...
| Autores: | , , , , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2004 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/415088 |
| Acceso en línea: | http://hdl.handle.net/10261/415088 https://api.elsevier.com/content/abstract/scopus_id/3042653269 |
| Access Level: | acceso abierto |
| Palabra clave: | http://metadata.un.org/sdg/9 http://metadata.un.org/sdg/7 Ensure access to affordable, reliable, sustainable and modern energy for all Build resilient infrastructure, promote inclusive and sustainable industrialization and foster innovation |
| Sumario: | The thermal degradation of Nomex [poly(m-phenylene isophthalamide)] impregnated with phosphoric acid has been investigated by the analysis of the corresponding pyrolysis products, which were fractionated into gases, liquids, and char. Gas chromatography (GC) and/or gas chromatography/mass spectrometry (GC/MS) were used to study the volatiles evolved whereas the solid residue was examined by elemental analysis and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). For the sake of comparison, a parallel study of unimpregnated Nomex was carried out in the same conditions. The main product of unimpregnated Nomex degradation in the conditions of this work was found to be m-benzenediamine, which is the result of a heterolytic process. Aromatic nitriles are also produced through homolytic reactions. Most of the products of impregnated Nomex degradation were also detected with its unimpregnated counterpart, except for isophthalic acid, carbon monoxide, and elemental phosphorus. Aromatic nitriles are the pre-eminent products from pyrolysis of unimpregnated Nomex, there being no trace of m-benzenediamine. Reaction mechanisms for impregnated Nomex degradation consistent with these findings are proposed, including a nonhomolytic process for the formation of nitriles in the presence of phosphoric acid. |
|---|