Search results for "Époxy"
showing 8 items of 8 documents
Contribution to the development of 100% bio-based composites : synthesis of bio-based polyepoxides, supercritical CO2 treatment of hemp fibers and im…
2018
This thesis contributes to the development of 100% bio-based hemp/epoxy composites. Current environmental issues favor the emergence of materials derived from renewable resources such as plant fibres and a wide range of bio-based building-blocks, source of epoxy prepolymers in particular. An intensive investigation of the two constituents (hemp fibres and polyepoxidic matrix) is carried out before the composites manufacturing. Supercritical CO2 treatment is applied to hemp fibres used as reinforcement in composite materials. This treatment, not optimized, leads to better individualization as well as a decrease in the hygroscopic power of the fibres. These aspects, which are essential in ord…
Synthèse et formulation de résines photopolymérisables issues de la biomasse : application pour l'impression Braille
2014
The work of the PhD deals with the synthesis of polymerizable monomers derived from biomass, the study of their photopolymerization and the characterization of the resulting materials. The formulated monomers were tested in a printing method of Braille characters.The monomers were prepared in a two-steps reaction that is simple, economic and environmentally friendly. The first step comprised a reaction between glycerol derivatives (glycerol carbonate or glycidol) and fatty acids. In the second step, the obtained [alpha]-monoglycerides were functionalized to obtain photopolymerizable monomers. The different obtained monomers that bear (meth)acrylate and/or epoxy groups were photopolymerized …
Development of bio-based epoxy systems for dry-impregnated vegetables fiber composites implementation
2022
Prepregs find industrial applications thanks to their high thermomechanical properties and easy implementation. However, they have two major drawback. First, they needto be carried and stored at low temperature. The second drawback is linked to the use of solvent in the future matrix, generating VOCs during thermocompression process. Those two points leads to environmental and economical overcharges resolved by a new dry impregnation process developed by Fibroline company. Those PhD works are reporting the synthesis and formulation of a biobased powder system with a low environmental impact, non-toxic for humans and compatible with dry impregnation for fully bio-based composites implementat…
Prise en eau par composites carbone/époxy et leur effet sur le comportement mécanique : application aux réparations de structures en composite par co…
2013
Le travail présenté dans ce mémoire avait pour objectif d’étudier le processus de la pénétration d'eau dans les composites en carbone/époxyde dans un premier temps, et dans un deuxième temps, d’étudier l’effet de la prise en eau par ces matériaux sur les performances mécaniques des composites et leur joints collés. L'intégration de ces phénomènes physiques dans la modélisation numérique est d'une grande importance dans la prédiction de la durabilité d’une structure en composite subissant un vieillissement hygrothermique. Par conséquent, ce travail consiste non seulement en des observations expérimentales, mais aussi en des simulations numériques. Des corrélations entre les résultats obtenus…
Development and characterization of a bio-based epoxy matrix for high-grade bio-based composites
2019
This study aims to develop 100% bio-based hemp/epoxy composites for semi-structural and structural applications. The thermal and mechanical performances of a 100% bio-based matrix derived from biomassare evaluated and reveal properties in the same order of magnitude as those obtained for polyepoxides based on DGEBA, that means a glass transition temperature of approximately 150°C and mechanical properties in the order of 120MPa for the maximum stress and 3.2 GPa for the tangent apparent modulus. This natural origin matrix is then used for the manufacture of composites reinforced with hemp rovings. The bending properties of these 100% bio-based materials are equivalent to those determined fo…
Development and characterization of a bio-based epoxy matrix for high-grade bio-based composites
2019
This study aims to develop 100% bio-based hemp/epoxy composites for semi-structural and structural applications. The thermal and mechanical performances of a 100% bio-based matrix derived from biomassare evaluated and reveal properties in the same order of magnitude as those obtained for polyepoxides based on DGEBA, that means a glass transition temperature of approximately 150°C and mechanical properties in the order of 120MPa for the maximum stress and 3.2 GPa for the tangent apparent modulus. This natural origin matrix is then used for the manufacture of composites reinforced with hemp rovings. The bending properties of these 100% bio-based materials are equivalent to those determined fo…
Influence Des Conditions De Fabrication Sur Les Propriétés Mécaniques Et Physico-Chimiques D'un Composite Lin/Époxy Unidirectionnel
2017
This study focused on the development of a manufacturing process of laminated composites made from DGEBA epoxy matrix and flax fibers. The aim is to produce a material with good and low dispersed mechanical properties. Thermocompression is the chosen manufacturing method because it enables the production of composite with high fiber content. We used separated matrix and reinforcement, and not a prepreg, to fully control each component of our composites. Several curing cycle parameters have been tested in order to optimize mechanical properties and processing time. A multi-scale analyze has been carried on the produced composites in order to quantify the range of properties’ modifications. T…
: Effects of process conditions on mechanical and physicochemical properties of unidirectional flax/epoxy composite
2017
National audience; This study focused on the development of a manufacturing process of laminated composites made from DGEBA epoxy matrix and flax fibers. The aim is to produce a material with good and low dispersed mechanical properties. Thermocompression is the chosen manufacturing method because it enables the production of composite with high fiber content. We used separated matrix and reinforcement, and not a prepreg, to fully control each component of our composites. Several curing cycle parameters have been tested in order to optimize mechanical properties and processing time. A multi-scale analyze has been carried on the produced composites in order to quantify the range of propertie…