Elucidating the role of alkoxy radicals in polyethylene radio-oxidation kinetics
| Autor: | Yunho Ahn, Guido Roma, Xavier Colin |
|---|---|
| Přispěvatelé: | Service de recherches de métallurgie physique (SRMP), Département des Matériaux pour le Nucléaire (DMN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), This work was granted access to the HPC resources of TGCC and CINES under the allocation 22010 and 2020-A0090906018 made by GENCI, European Project: 755183,NFRP-2016-2017-1,TeaM Cables |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Inorganic Chemistry
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry Chemical sciences Polymers and Plastics [CHIM.ORGA]Chemical Sciences/Organic chemistry Organic Chemistry Condensed matter Materials Chemistry [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] Polymères [Chimie] Soft condensed matter Sciences de l'ingénieur [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] |
| Zdroj: | Macromolecules Macromolecules, 2022, 55, pp.8676. ⟨10.1021/acs.macromol.2c01135⟩ |
| ISSN: | 0024-9297 1520-5835 |
| DOI: | 10.1021/acs.macromol.2c01135⟩ |
| Popis: | International audience; Polyethylene is a widely used polymer and a prototypical polyolefin. Understanding degradation mechanisms at the atomic scale leading to oxidation under the effect of temperature and/or irradiation is crucial for many long term applications. Here we focus on a subset of reactions belonging to the generally assumed reaction scheme and involving alkoxy radicals. We follow a theoretical approach based on density functional theory (DFT), in order to assess the role of these species, which are short lived and thus hard to detect experimentally. For every considered reaction we calculate the reaction enthalpy as well as the energy barrier and we evaluate the influence of the local atomic environment, taking advantage of a model surface of a crystalline lamella which mimicks the interface between crystalline and amorphous zones. Our results suggest that, in certain conditions, the kinetic pathway can bypass the formation of hydroperoxides. The concentrations of alkoxy and peroxy radicals during radio-oxidation, as well as their ratio, are important parameters controlling the predominance of chain-scission or crosslinking of the polymer. The data presented here constitute part of a database that can be used to set up kinetic simulations based on homogeneous chemical kinetics or Monte Carlo algorithms. |
| Databáze: | OpenAIRE |
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