From Ionic Liquid Epoxy Monomer to Tunable Epoxy–Amine Network: Reaction Mechanism and Final Properties

In this work, new (multi)­functional-dedicated polymer materials were designed and processed from the copolymerization between novel imidazolium ionic liquid monomer (ILM) with a conventional polyetheramine denoted Jeffamine D230. First, a facile and robust synthetic route was investigated in order to design polyfunctional imidazolium monomers bearing an aromatic ring and two epoxy functions at the end of aliphatic chains. Then, the main mechanisms of epoxy opening leading to polymerization with different kinetics were modeled through the reaction between a monofunctional epoxy and aliphatic mono- and diamines by using “in situ” NMR spectroscopy. Finally, the monomer molecular structure-network architecture-physical properties relationships of the resulting IL-modified epoxy networks were investigated. As a consequence, epoxy networks with a glass transition temperature of 55 °C and with enhanced properties such as thermal stability (>300 °C), storage modulus of 700 MPa at room temperature, and an ionic conductivity (4 × 10–4 S m–1 for 70 °C) combined with an hydrophobic character of their surface (33 mJ m–2) were prepared