Super-Crosslinked Ionic Liquid-Intercalated Montmorillonite/Epoxy Nanocomposites: Cure Kinetics, Viscoelastic Behavior and Thermal Degradation Mechanism Publisher



Seidi F¹ ; Jouyandeh M^{2, 3} ; Akbari V^{2, 3} ; Paran SMR² ; Livi S⁴ ; Ducos F⁵ ; Vahabi H³ ; Ganjali MR^{2, 6} ; Saeb MR⁷
Source: Polymer Engineering and Science Published:2020

Abstract

Super-crosslinked epoxy nanocomposites containing N-octadecyl-N′-octadecyl imidazolium iodide (IM)-functionalized montmorillonite (MMT-IM) nanoplatelets were developed and examined for cure kinetics, viscoelastic behavior and thermal degradation kinetics. The structure and morphology of MMT-IM were characterized by FTIR, XRD, TEM, and TGA. Synthesized MMT-IM revealed synergistic effects on the network formation, the glass transition temperature (Tg) and thermal stability of epoxy. Cure and viscoelastic behaviors of epoxy nanocomposites containing 0.1 wt% MMT and MMT-IM were compared based on DSC and DMA, respectively. Activation energy profile as a function of the extent of cure was obtained. DMA results indicated a strong interface between imidazole groups of MMT-IM and epoxy, which caused a significant improvement in storage modulus and the Tg of epoxy. Network degradation kinetics of epoxy containing 0.5, 2.0, and 5.0 wt% MMT and MMT-IM were compared by using Friedman, Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO) and the modified Coats-Redfern methods. Although addition of MMT to epoxy was detrimental to the Tg value, as featured by a fall from 94.1°C to 89.7°C detected by DMA method, and from 103.3°C to 97.9°C by DSC method, respectively. By contrast, meaningful increase in such values were observed in the same order from 94.1°C to 94.7°C and from 103.3°C to 104.7°C for super-crosslinked epoxy/MMT-IM systems. © 2020 Society of Plastics Engineers