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Doctoral thesis (Dissertations and theses)
Carbon dioxide and vegetable oil for the synthesis of biobased polymer precursors
Alves, Margot
2016
 

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Keywords :
supercritical carbon dioxide; polycarbonate
Abstract :
[en] Although it is a thermodynamically and kinetically stable molecule, carbon dioxide can be converted into five- and six-membered cyclic carbonates by coupling with epoxides or oxetanes, respectively, using appropriate catalysts. Cyclic carbonates are used as green solvents, electrolytes for Li-ion batteries or intermediates for the synthesis of polymers. However, the catalytic performance must be further enhanced in particular for the coupling of CO2 with epoxidized vegetable oils or oxetanes. In this context, we developed a new highly efficient bicomponent homogeneous organocatalyst composed of an ammonium salt as the catalyst and fluorinated single or double hydrogen bond donors as co-catalysts. First, a screening of onium-based catalysts and hydrogen-bond donors was performed. Performances of the catalysts and optimization of the reaction was realized through detailed kinetics studies using in-situ FTIR/Raman spectroscopy under pressure. We demonstrated that fluorinated alcohols showed unexpected co-catalytic activity due to synergisms between the onium salt and fluorinated co-catalysts enabling the fast and selective addition of CO2 onto model epoxides and epoxidized vegetable oils under solvent-free and mild experimental conditions. The use of this powerful dual catalyst was then extended to the first organocatalytic coupling of CO2 with less reactive oxetanes to produce hydroxyl telechelic oligocarbonates that were used as precursor of CO2-based polyurethanes by chain-extension with a diisocyanate. In addition, a fine comprehension of the mechanisms was investigated by DFT calculations highlighting that the co-catalytic performance of the onium salt/fluorinated alcohol binary catalyst arose from the strong stabilization of the intermediates and transitions states by hydrogen-bonding. To date, through comparative studies, we evidenced that this new catalyst is one of the most performing and versatile system enabling the coupling of CO2 both with epoxides or oxetanes.
Research center :
Center for Education and Research on Macromolecules (CERM)
CESAM - Complex and Entangled Systems from Atoms to Materials - ULiège
Disciplines :
Materials science & engineering
Chemistry
Author, co-author :
Alves, Margot ;  University of Liège - ULiège > Complex and Entangled Systems from Atoms to Materials (CESAM), Center for Education and Research on Macromolecules (CERM)
Language :
English
Title :
Carbon dioxide and vegetable oil for the synthesis of biobased polymer precursors
Alternative titles :
[fr] Valorisation du CO2 et d'huiles végétales pour la synthèse de monomères biosourcés
Defense date :
17 November 2016
Number of pages :
230
Institution :
ULiège - Université de Liège
Université de Bordeaux
Degree :
PhD Thesis
Promotor :
Jérôme, Christine  ;  Université de Liège - ULiège > Complex and Entangled Systems from Atoms to Materials (CESAM)
Tassaing, Thierry
President :
Vertruyen, Bénédicte  ;  Université de Liège - ULiège > Département de chimie (sciences)
Secretary :
Detrembleur, Christophe ;  Université de Liège - ULiège > Complex and Entangled Systems from Atoms to Materials (CESAM)
Jury member :
Kleij, Arjan
Aprile, Carmela
Didier, Benoit
Méreau, Raphaël
Funders :
University of Bordeaux through the "Initiative d’Excellence" (IDEX) program
The Walloon Region in the frame of the CO2green program
The International Doctoral School IDS-Funmat
Available on ORBi :
since 24 November 2016

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