Calorimetric analysis and molecular dynamics simulation of cure kinetics of epoxy/chitosan-modified Fe3O4 nanocomposites

Abstract

Fe3O4 magnetic nanoparticles (MNPs) were synthesized and modified with chitosan as a natural surface modifier to prevent their aggregation and make them potent to contribute to ring opening of epoxy. Functionalized Fe3O4 (Chitosan@Fe3O4) was characterized by Fourier transform infrared, thermogravimetric analysis, transmission electron microscope and magnetic hysteresis loops measurements. The cure behavior and kinetics of epoxy nanocomposites filled with bare and chitosan-modified Fe3O4 were analyzed using isothermal and nonisothermal differential scanning calorimetry (DSC). The kinetic models applied to DSC experimental data suggested positive effect of Chitosan@Fe3O4 MNPs on cure reaction between epoxy and polyamidoamine hardener. Experimental and modeling outcomes from epoxy/Chitosan@Fe3O4 nanocomposites were supported by theoretical quantum chemical calculations and molecular dynamics simulations. Computational studies demonstrated that curing of epoxy resin with aminoamide hardener has been governed by the interaction between epoxy and Chitosan@Fe3O4.