Computational and experimental study of mechanical properties of Nylon 6 nanocomposites reinforced with nanomilled cellulose

Abstract

Molecular dynamics simulation was carried out for Nylon 6 nanocomposites reinforced with nanocellulose with different compositions. Uniaxial deformation was carried out by applying strain providing the stress-strain behaviour of corresponding materials, from which the mechanical properties of the nanocomposites were predicted. Elastic constants were also determined by calculating the elastic stiffness matrix of the modelled systems. Density and temperature profile of the systems were investigated to resemble the experimentally prepared samples. Experimentally, tensile characteristics of nanocomposites were evaluated to validate the computational results. Nanocellulose was prepared from micro-crystalline cellulose via wet-stirred media milling optimizing different parameters. Cellulose nanoparticles were then used to reinforce nanocomposites via solution casting method. Fourier Transform Infrared (FTIR) spectroscopy confirmed the chemical composition of nylon and its nanocomposite. The mechanical analysis was performed using Universal Testing Machine (UTM) to obtain the elastic modulus and tensile strength of the materials. Scanning Electron Microscopy (SEM) gave the morphology of the nanocomposite showing the presence of dispersed nanoparticles in the polymer matrix. Dynamic Mechanical analysis (DMA) was performed to validate the glass transition temperature (Tg) derived from the simulations. Experimental results confirmed the trend featured in the simulation data, with nanocomposites having 3 wt% nanocellulose was considered as the optimum composition showcasing enhanced mechanical properties. This work proposes a simulation method to predict the mechanical behaviour of Nylon 6/nanocellulose nanocomposites, which was confirmed by reinforcing nanomilled nanocrystalline cellulose into Nylon 6 matrix and validating with tensile tests.