Le CO2 supercritique pour la synthèse de carbonates cycliques catalysée par des liquides ioniques (étude des propriétés thermodynamiques et des mécanismes réactionnels par spectroscopie vibrationnelle et modélisation moléculaire)

Ce travail de thèse vise à comprendre les propriétés thermodynamiques et les mécanismes réactionnels engendrés dans les réactions de cycloaddition d'époxydes en milieu CO2 supercritique catalysées par des liquides ioniques pour la synthèse de carbonates cycliques. Les propriétés thermodynamiques (solubilité, gonflement, diagramme de phase) des mélanges binaires époxyde/CO2 ont été déterminées pour des époxydes modèles et des époxydes dérivées d'huiles végétales. Des suivis cinétiques in-situ par spectroscopie IR-TF et Raman ont été effectués pour déterminer l'influence de la nature des liquides ioniques étudiés et des paramètres température-pression sur les cinétiques de réaction. Des modélisations moléculaires de type DFT nous ont permis de proposer un mécanisme réactionnel en accord avec les résultats expérimentaux et de bien comprendre quels sont les rôles respectifs de l'anion et du cation du liquide ionique dans la réaction.This thesis aims to understand the thermodynamic properties and reaction mechanisms generated in the cycloaddition reaction of epoxides in supercritical CO2 medium catalyzed by ionic liquids for the green synthesis of cyclic carbonates. Thermodynamic properties (solubility, swelling, phase diagram) of epoxide/CO2 binary mixtures were determined for commercial mono-epoxides and vegetable based epoxidized oils. Kinetics study in-situ by FTIR and Raman spectroscopy were performed to determine the influence of the nature of the ionic liquids studied and of different parameters such as temperature and pressure on the reaction. Molecular modeling using DFT method has helped us to propose a reaction mechanism consistent with the experimental results and to understand what are the respective roles of the anion and cation of the ionic liquid in the reaction.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

Palladium nanoparticles stabilized by novel choline-based ionic liquids in glycerol applied in hydrogenation reactions

Palladium nanoparticles stabilized by choline-based ionic liquids in glycerol were prepared from Pd(II) precursors by simply heating at 80 °C under argon; in this process, the water present in the ionic liquid was found to be responsible for the reduction of Pd(II) into zero-valent palladium species. Palladium nanoparticles were fully characterized in both liquid phase and solid state. The as-prepared metal nanoparticles exhibited remarkable catalytic activity in hydrogenation processes for a significant variety of functional groups (alkenes, alkynes, nitro derivatives, benzaldehydes, aromatic ketones)

Le CO2 supercritique pour la synthèse de carbonates cycliques catalysée par des liquides ioniques : étude des propriétés thermodynamiques et des mécanismes réactionnels par spectroscopie vibrationnelle et modélisation moléculaire

Ce travail de thèse vise à comprendre les propriétés thermodynamiques et les mécanismes réactionnels engendrés dans les réactions de cycloaddition d'époxydes en milieu CO2 supercritique catalysées par des liquides ioniques pour la synthèse de carbonates cycliques. Les propriétés thermodynamiques (solubilité, gonflement, diagramme de phase) des mélanges binaires époxyde/CO2 ont été déterminées pour des époxydes modèles et des époxydes dérivées d'huiles végétales. Des suivis cinétiques in-situ par spectroscopie IR-TF et Raman ont été effectués pour déterminer l'influence de la nature des liquides ioniques étudiés et des paramètres température-pression sur les cinétiques de réaction. Des modélisations moléculaires de type DFT nous ont permis de proposer un mécanisme réactionnel en accord avec les résultats expérimentaux et de bien comprendre quels sont les rôles respectifs de l'anion et du cation du liquide ionique dans la réaction.This thesis aims to understand the thermodynamic properties and reaction mechanisms generated in the cycloaddition reaction of epoxides in supercritical CO2 medium catalyzed by ionic liquids for the green synthesis of cyclic carbonates. Thermodynamic properties (solubility, swelling, phase diagram) of epoxide/CO2 binary mixtures were determined for commercial mono-epoxides and vegetable based epoxidized oils. Kinetics study in-situ by FTIR and Raman spectroscopy were performed to determine the influence of the nature of the ionic liquids studied and of different parameters such as temperature and pressure on the reaction. Molecular modeling using DFT method has helped us to propose a reaction mechanism consistent with the experimental results and to understand what are the respective roles of the anion and cation of the ionic liquid in the reaction

Le CO2 supercritique pour la synthèse de carbonates cycliques catalysée par des liquides ioniques : étude des propriétés thermodynamiques et des mécanismes réactionnels par spectroscopie vibrationnelle et modélisation moléculaire

Ce travail de thèse vise à comprendre les propriétés thermodynamiques et les mécanismes réactionnels engendrés dans les réactions de cycloaddition d'époxydes en milieu CO2 supercritique catalysées par des liquides ioniques pour la synthèse de carbonates cycliques. Les propriétés thermodynamiques (solubilité, gonflement, diagramme de phase) des mélanges binaires époxyde/CO2 ont été déterminées pour des époxydes modèles et des époxydes dérivées d'huiles végétales. Des suivis cinétiques in-situ par spectroscopie IR-TF et Raman ont été effectués pour déterminer l'influence de la nature des liquides ioniques étudiés et des paramètres température-pression sur les cinétiques de réaction. Des modélisations moléculaires de type DFT nous ont permis de proposer un mécanisme réactionnel en accord avec les résultats expérimentaux et de bien comprendre quels sont les rôles respectifs de l'anion et du cation du liquide ionique dans la réaction.This thesis aims to understand the thermodynamic properties and reaction mechanisms generated in the cycloaddition reaction of epoxides in supercritical CO2 medium catalyzed by ionic liquids for the green synthesis of cyclic carbonates. Thermodynamic properties (solubility, swelling, phase diagram) of epoxide/CO2 binary mixtures were determined for commercial mono-epoxides and vegetable based epoxidized oils. Kinetics study in-situ by FTIR and Raman spectroscopy were performed to determine the influence of the nature of the ionic liquids studied and of different parameters such as temperature and pressure on the reaction. Molecular modeling using DFT method has helped us to propose a reaction mechanism consistent with the experimental results and to understand what are the respective roles of the anion and cation of the ionic liquid in the reaction

In situ FTIR investigation of the solubility and swelling of model epoxides in supercritical CO2

The phase behavior of carbon dioxide/epoxide mixtures has been investigated using an efficient in situ FTIR method that allows us determining the evolution of the concentration of each component in the two phases (CO2-rich phase and epoxide-rich phase) as a function of temperature and pressure. The measurements have been performed for three different temperatures (40,70 and 100 degrees C) for pressures ranging between 0.1 and 20 MPa. We have selected propylene oxide (PO), styrene oxide (SO) and cyclohexene oxide (CO) molecules that are widely used in the synthesis of cyclic carbonates. Thus, we have determined the solubility of these epoxides in supercritical CO2 as well as the CO2 sorption and the resulting swelling of the epoxide rich phase. From these concentration measurements, we could establish the pressure-composition phase diagram of these epoxide/CO2 binary mixtures. (C) 2012 Elsevier B.V. All rights reserved

A synthetic-dynamic method for water solubility measurements in high pressure CO2 using ATR–FTIR spectroscopy

A new synthetic method for studying phase behaviour is described using Attenuated Total Reflection (ATR) spectroscopy. The method has been developed to provide relevant information on the solubility of water in CO2. The dew point of water has been determined at three different pressures, viz. (4.05, 5.05 and 6.03) MPa with mole fractions of water between 0.01 and 0.04. The data obtained fill the gap in the literature in these regions of pressures and temperatures and could be of high importance in the context of Carbon Capture and Storage (CCS) technology. Indeed, the presence of water in the captured CO2 could damage the pipeline used for CO2 transport. Hence, it is very important to have a fully understanding of the behaviour of the (CO2 + H2O) mixtures in wide range of temperature relevant for CCS

Novel green fatty acid-based bis-cyclic carbonates for the synthesis of isocyanate-free poly(hydroxyurethane amide)s

Fatty acid-based bis-cyclic 5-membered carbonates containing amide linkages were prepared from methyl 10-undecenoate. The reaction in bulk of these bio-based carbonates with a series of di-amines led to poly(hydroxyurethane amide)s with molar masses up to 31 000 g mol(-1). As expected, the so-formed bio-based thermoplastic poly(hydroxyurethane)s exhibit amorphous to semi-crystalline features with respect to the chemical structure of the monomers used

Solubility in CO 2 and swelling studies by in situIR spectroscopy of vegetable-based epoxidized oils as polyurethane precursors

The phase behaviour of carbon dioxide/Vegetable Based Epoxidized Oils (VBEO) mixtures has been investigated at three different temperatures (40, 70 and 100°C) and pressures ranging between 0.1 and 20 MPa. The measurements have been performed using an efficient in-situ FTIR method that allowed us to determine the variation of the concentration of each component in the two phases (CO2 rich phase and VBEO rich phase) as a function of temperature and pressure. Several epoxidized mono-, di- and tri-glyceride derivatives have been tested. The solubility of these epoxidized oils have been investigated in the CO2 rich phase and in the CO2 sorption and the resulting swelling of the VBEO rich phase. From these concentration measurements, we could establish the pressure-composition phase diagrams of these VBEO/CO2 binary mixtures. The three monoglyceride derivatives studied were found to be more soluble in CO2 and have a higher percentage of swelling than the VBEO which have a higher molecular weight. However, it was found that a significant amount of CO2 was incorporated in all these VBEO at relatively moderate pressures. Thus, we expect these VBEO to be good candidates for performing carbonation reaction to generate in good yields vegetable-based cyclic carbonates as polyurethane precursors