The Stress Analysis of Polymethyl Methacrylate (PMMA) Nanocube Using Molecular Dynamics Simulation

Abstract

Polymethyl methacrylate (PMMA) stands as a significant polymer, recognised for its unique combination of mechanical attributes, processing friendliness, and chemical stability [1]. The present study focuses on the use of molecular dynamics (MD) simulation to study the mechanical response of PMMA nanostructures to uniaxial tensile loading as an initial step to understanding the mechanisms of deformation, assessing the mechanical stability, and describing the tensile behaviour of PMMA at the nanoscale. To examine thermodynamic equilibrium, NVT—and NPT equilibria (NVT: number of particles, volume, and temperature; NPT: number of particles, pressure, and temperature) equilibrium simulations were performed along with deformation molecular configuration energy minimisation to ensure stable molecular configurations. These analyses were necessary for the advancement of PMMA to accommodate new flexible electronics, biomedical devices, and other nanotechnology systems. The nanostructures were designed in JMOL and PACKMOL software, and the simulation was executed in LAMMPS using the COMPASS force field. Structural stability was ensured by performing energy minimisation and equilibrating prior to tensile loading at 300 K and 1 atm under both NVT and NPT conditions. The findings show that PMMA nanostructures with greater aspect ratios show greater elongation under tension. The sequential stress–strain data contained separate and distinct regions of elastic and plastic deformation, which also helped to elucidate the mechanics of the material at the nanoscale and the constraints thereof. The mechanical performance of the studied PMMA nanostructures, when compared to bulk PMMA and other polymer nanostructures, was also superior and can be linked to the mechanical properties of the nanostructured morphology. This study enhances the knowledge of the PMMA in tension and provides a basis for the design and refinement of new advanced nanostructured polymeric materials. These findings should contribute to the fabrication of flexible electronics with greater durability, biomedical devices, and other applications in nanotechnology.