Cure kinetics of exfoliated bio-based epoxy/clay nanocomposites developed from acrylated epoxidized castor oil and diglycidyl ether bisphenol A networks

Abstract

A bio-based epoxy monomer was synthesized by acrylation of epoxidized castor oil (ECO). Subsequently, acrylated ECO (AECO)-toughened diglycidyl ether of bisphenol A (DGEBA) nanocomposites were prepared via sol–gel process with the addition of organically treated montmorillonite nanoclays. In this study, the curing kinetics of anhydride-cured DGEBA/AECO monomer with and without clays was studied by non-isothermal differential scanning calorimetry analysis. The apparent activation energy obtained by Flynn–Wall–Ozawa method was reduced from 63 to 59 kJ mol⁻¹ and 69 to 61 kJ mol⁻¹, respectively, with the addition of 1 wt% clay to the DGEBA/10 wt% AECO and DGEBA/20 wt% AECO systems, respectively. The two-parameter Šesták–Berggren autocatalytic model was used to obtain the reaction orders m and n, respectively. The curves obtained by the Málek method show good agreement with the experimental data for bio-based epoxy systems.