Epoxy resin crosslinked with conventional and deep eutectic ionic liquids

Abstract

Epoxy resin crosslinked with conventional and deep eutectic ionic liquids Summary-Molecular ionic liquid, i.e. 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) and eutectic mixture of imidazole with choline chloride (IM + ChCl) have been used as epoxy resin hardeners. An influence of [EMIM]Cl and IM + ChCl content on pot life of epoxy compositions and runs of crosslinking process has been evaluated using DSC and ARES rheometry techniques. Epoxy compositions with [EMIM]Cl showed latent properties (pot life up to 50 days) while the systems with IM + ChCl gelled after few days. Comparative measurement of thermomechanical (T g , tan d) and mechanical properties (tensile, flexural and shear strength on aluminum substrates) as well as thermal decomposition of epoxy composites have been performed. Composite epoxy materials crosslinked with [EMIM]Cl exhibited more elastic properties (lower T g and higher tan d values) and generally better mechanical features than those hardened with imidazole + choline chloride eutectic mixture.

High performance epoxy composites cured with ionic liquids

“…The ionic liquids (ILs) can be used as catalytic epoxy resin crosslinkers solely [1][2][3][4][5][6][7] or in combination with other conventional hardeners, such as polyamines [3,[8][9][10][11] or anhydrides [12,13]. Epoxy compositions with ILs exhibited latency at room temperature which could be regulated in a rather wide range from a few days (e.g.…”

“…3-4, for systems with 1-butyl-3-methylimidazolium thiocyanate, [BMIM]SCN, [7] or phosphonium phosphinate derivative [6,14]) up to ca. 50 days (imidazolium ILs with chloride or tetrafluoroborate anions [4,5]) when used in similar weight ratio to epoxy resin (3 parts per 100 parts of resin, 3 phr). Besides the mentioned latent character, to important advantages of ILs as epoxy resin curing agents belong low loading (usually 3-9 phr), fast and easy miscibility as well as homogeneity with liquid epoxy resin (before and after curing process) resulting in technological feasibility.…”

Epoxy resin/phosphonium ionic liquid/carbon nanofiller systems: Chemorheology and properties

“…ILs have been used together with polyamine or anhydride hardeners in order to modify epoxy curing process as well as materials glass transition temperature [7,8], lubrication [6], or to improve (nano)filler dispersion [9][10][11]. The epoxy compositions with the most often used 1-alkyl-3-methylimidazolium ILs exhibited pot life at ambient temperature: 50-60 days where counteranions were chloride or tetrafluoroborate (3 wt parts/ 100 wt parts of epoxy resin, 3 phr) [4,12]. That parameter was shortened to 30 days when 1-butyl-3-methylimidazolium (BMIM) with dicyanamide anion [2] or even to 3 days when BMIM with thiocyanate anion [5] was used (at 3 phr).…”

Composition as a Means To Control Morphology and Properties of Epoxy Based Dual-Phase Structural Electrolytes

“…34,40 , the performance of the epoxy can be modulated, since many ILs can be used as curing agents. 31,33,[41][42][43][44] In addition, the properties/structure (morphology) of the epoxy/IL blends and resulting cured epoxies can be adjusted, for example to improve wear and scratch resistance, 32, 33 thermal stability 44 or ion conduction. 10,18 In an earlier study, we described a strong effect of the morphology on the properties of electrolytes based on a blend of an epoxy/amine system and a lithium salt doped IL 10 ; the conclusion was that a relatively coarse bicontinuous structure is the most promising for structural electrochemical applications.…”