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| Le Gac, Pierre-yves; Choqueuse, Dominique; Paris, Marc; Recher, G.; Zimmer, Celine; Melot, D.. |
| In the offshore industry polymer coatings are widely used to ensure thermal insulation of steel pipes, and to avoid over-cooling of the hot oil inside. Because of very severe service conditions (i.e. high temperature, high pressure and presence of seawater) and an expected life time of 20 years, durability of these coatings is a major issue for this industry. Polypropylene and polyurethane are often used for this application, nevertheless these polymers have some limitations in terms of processing time for polypropylene and maximum service temperature for polyurethane. Polycyclopentadiene (pDCPD) shows good processing characteristics and low thermal conductivity, so this polymer could be a good alternative coating in the offshore industry, but the... |
| Tipo: Text |
Palavras-chave: Polydicyclopentadiene; Seawater; Accelerated ageing; Oxidation; Offshore; Field joint. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00114/22534/20233.pdf |
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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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| Richaud, Emmanuel; Le Gac, Pierre-yves; Verdu, Jacques. |
| Thermal ageing of thin films of unstabilized polydicyclopentadiene (pDCPD) at several temperatures ranging from 120 to 30°C was investigated by means of carbonyl build up by FTIR with ammonia derivatization, double bond titration, mass uptake measurement, hydroperoxides titration by iodometry and DSC coupled with sulfur dioxide treatment. In the temperature range under investigation, pDCPD is in glassy state and it oxidizes faster than common polymers oxidized at rubbery state (e.g. polydienic elastomers). Using the kinetic analysis, these results were ascribed to increased initiation rate due to catalyst residues, some possible intramolecular processes favoring propagation, or a very low termination rate of oxidation radical chains because of the control... |
| Tipo: Text |
Palavras-chave: Polydicyclopentadiene; Thermal oxidation; Kinetics; Molecular mobility. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28646/27073.pdf |
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