A synergic effect of CNT/Al<sub>2</sub>O<sub>3</sub> reinforcements on multiscale epoxy-based glass fiber composite: fabrication and molecular dynamics modeling
Davood Roustazadeh, Farshid Aghadavoudi, Amirsalar Khandan
Abstract
The multiscale nanocomposites are a new class of the designed materials that have nano and micro-scale reinforcements. The main purpose of this paper is to investigate the mechanical properties such as tensile and bending properties of a four-phase nanocomposite using molecular dynamics (MD) simulation and experimental evaluations. The nanocomposite constituents are carbon nanotubes (CNT), alumina nanoparticles (Al2O3), and glass fiber as reinforcements and epoxy resin as the matrix. Two atomistic models of nanocomposites were made with the cross-linked epoxy molecules as matrix and CNT and Al2O3 as reinforcements. After using NVT and NPT ensembles, the mechanical properties of the molecular models have been extracted using constant-strain method. An equation was proposed to predict the elastic modulus of the multiscale composite using the results of MD. Eight laboratory samples have been fabricated and empirical tensile and bending properties of these cases have been extracted. The characteristics of experimental samples were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The obtained results show that adding CNT and alumina to the polymer increased the tensile and bending moduli by 163% and 11%, respectively. Moreover, the nanoscale reinforcements enhanced the tensile and flexural strengths of classic glass fiber composite by about 28% and 13%. Comparing the empirical and simulation results show slight differences between the experimental data and predicted values using formula.