Radio-oxidation mechanisms of polyethylene and the role of antioxidants: atomic scale simulations
Description
Polyethylene (PE) is one of the most abundantly manufactured polymers for various applications. Among the various them, PE has been widely used as insulation of electrical cables in nuclear power plants (NPPs). However, because cable insulators consisting of polymers are most vulnerable in cable structures under high temperature or irradiation conditions (e.g., γ-rays), understanding the kinetic mechanisms involved in the polymer degradation is essential to ensure their long operation lifetime. This thesis study, based on density functional theory (DFT), aims to elucidate the degradation mechanisms of polyethylene mainly resulting from oxidation under irradiation, the so-called radio-oxidation process, that crucially triggers the aging of cables. Besides, antioxidants are commonly used as additives in order to slow down the aging process. The role of antioxidants and their action mechanism are carefully studied. The insight that is expected might find application in various fields, from electrical cable insulation in nuclear power stations to plastics used in everyday life. (author)
Abstract (French)
Le polyethylene (PE) est l'un des polymeres les plus abondamment fabriques pour diverses applications. Parmi ces applications, le PE a ete largement utilise comme isolant de cables electriques dans les centrales nucleaires (NPP). Cependant, etant donne que les isolants en polymeres constituent le maillon le plus vulnerable de la globalite du cable sous des conditions de haute temperature ou d'irradiation (par exemple, les rayons γ), la comprehension des mecanismes cinetiques de degradation est essentielle pour assurer une duree de vie la plus longue possible de ce composant en conditions operationnelles. L'etude menee dans cette these, basee sur la theorie fonctionnelle de la densite (DFT), vise a elucider les mecanismes de degradation du polyethylene resultant principalement de l'oxydation sous irradiation, ou radio-oxydation, qui joue un role crucial dans le declenchement du vieillissement des cables. Par ailleurs, les antioxydants sont couramment utilises comme additifs afin de ralentir le processus de vieillissement. Le role des antioxydants et leur mecanisme d'action sont soigneusement etudies. Les resultats attendus pourraient trouver une application dans divers domaines, de l'isolation des cables electriques dans les centrales nucleaires aux plastiques utilises dans la vie quotidienne
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Additional details
Additional titles
- Original title (English)
- Mecanismes de radio-oxydation du polyethylene et role des antioxydants: simulations a l'echelle atomique
Publishing Information
- Imprint Pagination
- 160 p.
- Report number
- FRCEA-TH--16259
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 54102293
- Subject category
- S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- AGING; ANTIOXIDANTS; DENSITY FUNCTIONAL METHOD; ELECTRIC CABLES; ELECTRICAL INSULATORS; KINETICS; OXIDATION; PHYSICAL RADIATION EFFECTS; POLYETHYLENES; POLYMERS
- Descriptors DEC
- CABLES; CALCULATION METHODS; CHEMICAL REACTIONS; CONDUCTOR DEVICES; ELECTRICAL EQUIPMENT; EQUIPMENT; ORGANIC COMPOUNDS; ORGANIC POLYMERS; POLYMERS; POLYOLEFINS; RADIATION EFFECTS; VARIATIONAL METHODS
Optional Information
- Notes
- 219 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses