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| Defauchy, Virginie; Le Gac, Pierre-yves; Guinault, Alain; Verdu, Jacques; Recher, Gilles; Drozdzak, Renata; Richaud, Emmanuel. |
| The in situ thermal oxidation of thin unstabilized polydicyclopentadiene was studied by TGA to monitor mass gain, and DSC to characterize hydroperoxides concentration. Results were discussed using kinetic analysis, which allowed the estimation of activation energies for key reactions of the oxidation process. Activation energy for termination was shown to be higher than in hydrocarbon liquids, which was discussed from the theory of diffusion controlled reactions, and a possible link with local motions associated with sub-glassy transition. Activation energy of thermal decomposition of hydroperoxides was found lower than for model hydroperoxides, suggesting an accelerating effect of organometallic catalysts. Despite those two results that indicate a poor... |
| Tipo: Text |
Palavras-chave: Polydicyclopentadiene; Thermal oxidation; Segmental mobility; Catalysis; Diffusion limited oxidation. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00388/49904/50476.pdf |
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| Huang, Jing; Minne, Wendy; Drozdzak, Renata; Recher, Gilles; Le Gac, Pierre Yves; Richaud, Emmanuel. |
| Thin unstabilized PDCPD film were thermally oxidized in ovens at several temperatures ranging from 50 °C to 120 °C. Hydroperoxide concentration was monitored by DSC. It was observed that hydroperoxides concentration reaches a plateau with short induction times, for example around 8 h at 50 °C. This plateau occurs at very high concentration, around about 1 mol l−1 at 50 °C. In order to study both the chemical mechanisms and the kinetics of hydroperoxides decomposition, oxidized samples were thermally aged in an inert atmosphere to destroy hydroperoxides. For initially high concentrations corresponding to the “plateau”, it was shown that hydroperoxides decompose following a bimolecular process, the rate constant of which being calculated from the... |
| Tipo: Text |
Palavras-chave: Polydicyclopentadiene; Thermal oxidation; Hydroperoxide decomposition; Polymerization catalysts. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00609/72080/70798.pdf |
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