Degradation mechanism of poly(ether‐urethane) Estane® induced by high‐energy radiation. II. Oxidation effects |
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| Authors: | A Dannoux S Esnouf B Amekraz V Dauvois C Moulin |
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| Institution: | 1. Laboratoire de spéciation des radionucléides et des molécules, DEN/DANS/DPC/SECR, Commissariat á L'Energie Atomique (CEA), Saclay, 91191 Gif/Yvette Cedex, France;2. Laboratoire des solides irradiés (UMR 7642), DSM/DRECAM, Ecole Polytechnique, 91128 Palaiseau Cedex, France |
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| Abstract: | To predict long‐term polymer behavior during a nuclear waste storage time, radiation effects on a segmented aromatic poly(ether‐urethane) induced by high‐energy radiation under oxygen atmosphere were investigated. To obtain a predictive model of polymer radio‐oxidation during several centuries, the first step consists to elaborate the elementary degradation mechanisms. Thus, electron paramagnetic resonance (EPR), Fourier transform infra‐red spectroscopy (FT‐IR), electrospray ionisation‐mass spectrometry (ESI‐MS), and gas mass spectrometry were carried out to identify radicals, chemical modifications, and gases to reach the radio‐oxidative mechanism at doses inferior than 1000 kGy. Degradation mainly occurs at urethane bonds and in polyether soft segments that produces stable oxidative products as formates, alcohols, carboxylic acids and H2, CO2 and CO gases. Predominant degradation occurred at polyether soft segments and crosslinking is in competition with scission. On the basis of the results, a mechanism of degradation for aromatic poly(ether‐urethane) is proposed. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 861–878, 2008 |
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| Keywords: | EPR FT‐IR irradiation mass spectrometry polyurethane |
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