Advanced bio-based epoxies and furanics thermosets – hierarchically assembled macromolecular design
Lundi 15 juin 2015
à 9h30 en salle C. Brot
The research work presented in this thesis was oriented on advanced thermoset materials and also on the conception of bio-based polymers and composites. This last topic has been investigated by the combination of different bio-based raw materials which are well-known to have a great potential to substitute the petroleum monomers. Firstly, a fundamental work has been done on the combination of epoxidized linseed oil (ELO) and anhydrides as cross-linkers, which links the polymerization reactivity with the network structure and thermomechanical properties. For being economically realistic, the bio-refineries are urged to valorize the side-stream products issued from biomass conversion. In that respect, a second study investigated successfully the incorporation and copolymerization of an important amount of humins (heterogeneous residues obtained during the sugar conversion into hydroxymethylfurfural (HMF)) with furfuryl alcohol (FA) in order to create new resins. Another proposed combination, focused on ELO and FA cationic copolymerization with the purpose to create new fully bio-based resins with tailored mechanical properties. Concerning the elaboration of advanced polymers and composites, a reflection around the hierarchically organized natural materials has been achieved in order to adapt the self-organization and structuration concepts to polymeric network. Herein, an inorganic-hybride orientable nanofiller (m-Sep) has been synthetized through the covalent grafting of magnetite nanoparticles under sepiolite surface. The obtained hybrid of m-Sep was ulterior “frozen” in different orientations in a thermoset matrix, and it’s anistropic mechanical responses have been highlighted. Finally, the conception of multi-scale ordered materials has been explored through the synthesis of an epoxidized liquid-crystalline monomer with a star-shape geometry. Then, the cross-linking process of this monomer has been studied in terms of polymerization kinetics and self-organization in correlation with the mechanical properties.
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