ie9b06574_si_001.pdf (484.05 kB)
Dual-Functionalized Imidazolium Ionic Liquids as Curing Agents for Epoxy Resins
journal contribution
posted on 2020-02-05, 13:04 authored by Zhiyi Jiang, Qingchen Wang, Long Liu, Yanqiang Zhang, Fang Du, Aimin PangAs epoxy resin curing agents, ionic liquids can help
improve mechanical properties, flame retardancy, and wear and tear
self-healing and extend the pot life of epoxy compositions. The functional
design of ionic-liquid curing agents may significantly improve the
overall performance of epoxy resins. In this paper, a series of dual-functionalized
ionic liquids, e.g., 1-(3-amino-3-oxopropyl)-3-propynyl-imidazolium,
1-(3-amino-3-oxopropyl)-3-(2-amino-2-oxoethyl)-imidazolium, and 1-allyl-3-(2-amino-2-oxoethyl)-imidazolium
combined with dicyanamide (N(CN)2–) or
bis(trifluoromethylsulfonyl)imide (NTf2–) anions, were synthesized and characterized as curing agents for
diglycidyl-4,5-epoxy-cyclohexane-1,2-dicarboxylate (TDE-85). The results
showed that the obtained bifunctional ionic liquids can be used as
a medium or high-temperature curing agents for TDE-85 with the curing
temperature range of 130–208 °C and the best mass ratio
range of 15:100–40:100. Thermosets obtained from the bifunctional
ionic liquid and TDE-85 curing system exhibit better heat resistance
with the glass transition temperature of 187–212 °C and
the decomposition temperature at 10% weight loss of 282–357
°C. The curing reaction mechanism of the 1-(3-amino-3-oxopropyl)-3-(2-amino-2-oxoethyl)-imidazolium
NTf2–/TDE-85 system mainly has three
processes.