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

Abstract

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.

Comparison of poly(ethylene glycol)-based networks obtained by cationic ring opening polymerization of neutral and 1,2,3-triazolium diepoxy monomers

“…In conclusion, we reported an original and straightforward synthetic pathway towards monocomponent cross-linked ion conducting networks. In contrast to previous reports based on diepoxy ILMs and diamine hardeners, 46,50,51 we showed here that the bulk cationic ring opening homopolymerization of a liquid diepoxy 1,2,3-triazolium ILM (i.e. DET 5) readily affords PIL networks without using a comonomer which fatally dilutes the ionic species.…”

“…48 Difunctional epoxy monomers can yield cross-linked networks either by stepgrowth polymerizations with comonomers such as diamines or by catalytic chain-growth ring opening polymerization or copolymerization with cyclic anhydrides. Although there has been a significant amount of work regarding the preparation of PIL-based cross-linked solid electrolytes by step-growth copolymerization of epoxy or diepoxy ILMs using the epoxy-amine reaction, 46,[49][50][51] to the best of our knowledge neither the cationic nor the anionic ROPs of diepoxy ILMs have been investigated so far.…”

Molecular-Level Investigation of Cycloaliphatic Epoxidised Ionic Liquids as a New Generation of Monomers for Versatile Poly(Ionic Liquids)

“…The elevated degradation temperatures support our previous works and further confirm the high thermal stabilities of imidazolium-based ILs bearing Tf N as counter-ion. Not surprisingly, CEIL-3 presented greater thermal stability, probably due to the higher physicochemical stability of ether groups compared to esters (see Figure 4 ) [ 20 , 42 ].…”

Molecular Size Effect on Curing Process for Epoxy and Amine Mixture

“…Epoxy resins are widely used in a variety of applications from structural materials to modern devices due to their excellent thermal and mechanical properties [1][2][3] . Also, since there is a degree of freedom in selecting epoxy as the base resin and amine as the curing agent, it is possible to select an appropriate mixture suitable for the desired properties by combining them, which is another factor for widening the application [4][5][6][7][8][9][10][11][12] . In addition, as further properties and/or functions are desired on to the epoxy resin, a number of components are supposed to be mixed in it.…”