Molecular Dynamics Simulations of Al2O3/Epoxy Nano-composite with Improved Heat-Resistance and Elastic Modulus

Abstract

Thermal and mechanical properties of Al2O3/epoxy nano-composite, composed of bisphenol A diglygde ether (DGEBA) as matrix and 3,3-diaminodiphenyl sulfone (DDS) as curing agent filled with Al2O3 nanoparticles in sphere, cubic or tetrahedron shapes, are investigated through molecular dynamics simulations. Constant temperature constant pressure (NPT) ensembles and annealing cycles are utilized for modeling thermodynamic equilibrium systems in a wide temperature range. It is verified that all the three shaped Al2O3 nano-fillers can effectively improve heat-resistant and mechanical performances of epoxy polymer, in which sphere Al2O3 nano-fillers are the most significant in promoting mechanical stiffness and render an elevated glass transition temperature by 13.5 K. All three different shaped Al2O3 nano-fillers are capable of efficiently reduce thermal expansion coefficient and fractional free volume(FFV), accounting for the evident improvement in heat resistance, in which sphere and cubic Al2O3 nano-fillers are more preferential for decreasing thermal expansion coefficient by 13.92% and 12.66% respectively. Al2O3/epoxy nano-composite represents a substantial amelioration in elastic modulus, which is especially significant in the temperature range around glass transition temperature.