The Mechanical Behaviors of Polyethylene/Silver Nanoparticle Composites: an Insight from Molecular Dynamics study

This research uses molecular dynamics simulation (MD) to study the mechanical properties of pristine polyethylene (PE) and its composites which include silver nanoparticles (PE/AgNPs) at two AgNP weight fractions of 1.05wt% and 3.10wt%. The stress-strain distribution of the tensile process shows that the embedded AgNPs can significantly improve the Young's modulus and tensile strength of the pristine PE, due to improvements in the local density and strength of the PE near the AgNP surface in the range of 12 angstrom. Regarding the effect of temperature on the mechanical properties of pristine PE and PE/AgNP composites, the Young's modulus and the strength of the pristine PE and PE/AgNP composites decreased significantly at 350K and 450K, respectively, consistent with predicted melting temperature of pristine PE, which lies at around 360K. At such temperatures as these, PE material has stronger ductility and a higher mobility of AgNPs in the PE matrix than those at 300K. With the increase of tensile strain, AgNPs tend to be close, and the fracture of PE leads to a similarity between both the Young's modulus and ultimate strength found for the pristine PE and those found for the PE/AgNP composites at 350K and 450K, respectively.