Mechanical and fracture behavior of MWCNT/ZrO2/epoxy nanocomposite systems: Experimental and numerical study

Abstract

Although carbon nanotubes (CNTs) have displayed great potential for enhancement of multifunctional properties of a polymer matrix, still incorporation of CNTs with the polymeric matrices requires further improvement in terms synthesis, processing, functionalization etc. In this study, we decorated the surfaces of multi-walled CNTs (MWCNTs) by zirconium dioxide (ZrO2) nanoparticles to fully utilize former's remarkable mechanical properties, and then MWCNT/ZrO2-based hybrid epoxy nanocomposites (MNCs) were synthesized via a novel ultrasonic dual mixing (UDM) technique. The fracture strength and toughness of prepared MNCs were studied using a 3-point (3-P) single edge notch bending test. The surface morphology and fracture mechanisms were examined through field emission scanning electron microscope images of the fracture surfaces of samples of MNCs. Apart from experimental investigations, the mechanics of materials (MOM) and finite element (FE) models were also developed to predict the effective elastic properties of two- and three-phase MNCs. The mechanical response of MNC-based beams was studied using 3-P bending test via FE simulations and the numerical predictions are found to be in good agreement with the experimental results with maximum discrepancy of ~6% at 1 wt% loading of hybrid nanofillers. Our results also reveal that the fracture toughness of MNCs is improved by ~31% compared to the neat epoxy when 1.0 wt% loading of MWCNT/ZrO2 hybrid nanofillers is used to fabricate MNC. © 2020 Society of Plastics Engineers