Abstract
Climate change accelerates the devaluation of chestnut tree sanitary initially due to a lack of silviculture and exploitation assigned to the considerable parceling out of the Cévennes forest. Therefore, the durability of the chestnut grove in this territory is reassessed. Local stakeholders have decided to entrust scientists for exploring new solutions offered by wood chemistry, as the wood quality provided by traditional lumber activities being less profitable. Green chemistry appears as a possible pathway because of the high content of extractives in chestnut wood such as ellagitannins and ellagic acid. This work aims to evaluate the use of chestnut wood extracts in the fields of flame retardants and biobased epoxy resins. The first part of this work succeeds to produce extracts with a large chemical diversity and investigates the relations between chemical compositions and thermal properties. The relative proportions between the two molecular families of the extracts – saccharides and phenolic components – induced modifications of combustion energy values and char residues. The second part discusses the effectiveness of two chestnut wood components, i.e. gallic and ellagic acids, for fireproofing epoxy resin by additive synthesis. The comparison with their boron derivatives indicates an improvement of the fire properties of the material by acting in the condensed phase. The third part is devoted to the synthesis of epoxy prepolymers, potential substitutes of bisphenol A diglycidyl ether from ellagic acid. The chemical addition of epoxy functional groups, which are epoxy prepolymer characteristics, was performed by allylation of phenolic hydroxyls followed by oxidation of allylic double bonds. The formulation of the prepolymer with two hardeners allowed producing resins having better flame retardant properties than the oil based reference.