Biobased Thermosetting Epoxy: Present and Future

The works undertaken to obtain either partially or fully biobased epoxide materials are studied. The reaction between the phenate ion and ECH 2 reveals two competitive mechanisms, one-step nucleophilic substitution with cleavage of the C-Cl bond and a two-step mechanism based on ring opening of ECH (2) with ArO- (1') followed by intramolecular cyclization (SNi) of the corresponding alcoholate, containing one atom of chlorine in the β-position, formed in situ. Depending on the substituent position or nature in the phenol, it takes 6-20 h at reflux or 24-26 h at room temperature to complete the reaction. The reaction of ECH with an alcohol is more difficult, with many side reactions, since this reaction generates new alcohol groups with similar pKa values which are able to react with the epoxy group of ECH, thus leading to its homopolymerization. Epoxies are able to react with (meth)acrylic acid to give formulations for coating applications or vinyl ester monomers and networks after radical polymerization.