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Clapiers, France

A method for manufacturing a profiled section made of a thermally insulating composite material. A thermoset matrix is injected into an injection box where continuous natural fiber rovings circulate. The continuous natural fiber rovings and a portion of the thermoset matrix are pultruded. The natural fiber volume ratio is between 50 and 70% and a natural fiber mass ratio is between 55 and 75%. During the injection step, the ratio of natural fibers can be adapted so that the composite material has a conductivity of less than 0.30. The continuous natural fiber rovings can be twisted before the steps of injecting and pultruding. Preferably, during the twisting step, a number of turns per meter of between 10 and 30 is transmitted to the continuous natural fiber rovings.

Jaillet F.,Innobat | Jaillet F.,Charles Gerhardt Institute | Nouailhas H.,Innobat | Auvergne R.,Charles Gerhardt Institute | And 3 more authors.
European Journal of Lipid Science and Technology | Year: 2014

A novel thermosetting vinylester (VE) resin was prepared form cardanol, coming from cashew nut shell liquid (CNSL), a renewable resource and waste of the cashew industry. A VE cardanol-based prepolymer was synthesized by reacting commercial cardanol diepoxy and methacrylic acid. The VE cardanol-based prepolymer was polymerized by free radical polymerization to yield a thermoset resin with different monomers used as reactive diluents such as styrene (ST), isobornyl methacrylate (IBOMA), dibutyl itaconate (DBI), butanediol dimethacrylate (BDDMA), and hexanediol dimethacrylate (HDDMA). The resulting VE resin was characterized by TGA, DSC, and DMA analyses and compared to diglycidyl ether of bisphenol A (DGEBA)-based VE resin. Cardanol-based VE resins exhibit interesting mechanical and thermal properties for composite materials. The Tg value is 86°C with 40% by mass of ST and 116°C with 40% by mass of IBOMA. Around 70°C of Tg are lost compared to DGEBA-based VE resin, whereas with an oil-based VE resin the loss of Tg value is around 150°C. Practical application: The acrylated cardanol-based monomer described in this contribution, that is, acrylated cardanol from CNSL, provided new biobased aromatic building blocks for further free radical polymerizations with various reactive diluents. The obtained VE materials are partially biobased and may be used as binders in composite applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Benyahya S.,Innobat | Benyahya S.,Charles Gerhardt Institute | Aouf C.,French National Institute for Agricultural Research | Aouf C.,Montpellier SupAgro | And 8 more authors.
Industrial Crops and Products | Year: 2014

Phenolic extract from the green tea leaves was used for the production of thermoset epoxy resins. The commercial green tea extract (GTE) was functionalized by the reaction with epichlorohydrin in the presence of phase transfer catalyst. The glycidyl ether derivative of the green tea extract (GEGTE) obtained with a good yield was cured in epoxy polymer with isophorone diamine (IPD) and the resulting network was compared to catechin-IPD and diglycidyl ether of bisphenol A (DGEBA-IPD) systems. The thermal and mechanical analyses of this bio-based epoxy polymer showed its high reactivity associated with a high crosslinking density (Tg: 140-190°C), a high thermal resistance and interesting mechanical properties. © 2014 Elsevier B.V.

Nouailhas H.,Innobat | Aouf C.,French National Institute for Agricultural Research | Aouf C.,Montpellier SupAgro | Aouf C.,Montpellier University | And 8 more authors.
Journal of Polymer Science, Part A: Polymer Chemistry | Year: 2011

Biobased epoxy resins were synthesized from a catechin molecule, one of the repetitive units in natural flavonoid biopolymers also named condensed tannins. The reactivity of catechin toward epichlorohydrin to form glycidyl ether derivatives was studied using two model compounds, resorcinol and 4-methylcatechol, which represent the A and B rings of catechin, respectively. These model molecules clearly showed differences in reactivity upon glycidylation, explaining the results found with catechin monomer. The reaction products were characterized by both FTIR and NMR spectroscopy and chemical assay. The glycidyl ether of catechin (GEC) was successfully cured in various epoxy resin formulations. The GECs thermal properties showed that these new synthesized epoxy resins displayed interesting properties compared to the commercial diglycidyl ether of bisphenol A (DGEBA). For instance, when incorporated up to 50% into the DGEBA resin, GEC did not modify the glass-transition temperature. Epoxy resins formulated with GEC had slightly lower storage moduli but induced a decrease of the swelling percentage, suggesting that GEC-enhanced crosslinking in the epoxy resin networks. © 2011 Wiley Periodicals, Inc.

Aouf C.,French National Institute for Agricultural Research | Aouf C.,Montpellier SupAgro | Aouf C.,Montpellier University | Nouailhas H.,Innobat | And 6 more authors.
European Polymer Journal | Year: 2013

Novel biobased epoxy thermoset was synthesized from gallic acid, a phenolic acid encountered in various plants, both in its simple form and as a part of gallotannins. The functionalization of gallic acid was carried out using a two-step synthesis involving the allylation of OH groups followed by the epoxidation of resulting double bonds. The performance of two oxygen transfer agents (meta-chloroperbenzoic acid (mCPBA) and methyl(trifluoromethyl) dioxirane generated in situ from 1,1,1-trifluoroacetone and oxone) was evaluated in the epoxidation of the allylic double bonds. The glycidyl derivative of gallic acid (GEGA) obtained from mCPBA epoxidation was cured in epoxy polymer formulation with isophorone diamine (IPDA). The thermal and mechanical preliminary analyses showed that this new epoxy network based on GEGA displayed interesting properties compared to the epoxy polymer formulated with commercial diglycidyl ether of bisphenol A (DGEBA). A higher glass-transition temperature of GEGA/IPDA epoxy resin indicates a higher crosslinking density of this network. © 2013 Elsevier B.V. All rights reserved.

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