Molecular dynamics simulation and experiment on analyzing mechanical properties of PMMA/SiO₂ composites based on interfacial interaction

In this paper, we investigate the impact of modified SiO2 nanoparticles on the mechanical properties of Polymethyl methacrylate (PMMA) composites through a combination of molecular dynamics simulation and experimentation. Our investigation focuses on analyzing the elastic modulus, bulk modulus, shear modulus, and Cauchy ratio of pure PMMA, PMMA/SiO2 composites, and PMMA/modified SiO2 composites over a temperature range of 200-400 K. Our results indicate that, as the temperature increases, the elastic modulus, bulk modulus, and Cauchy ratio of all materials decrease, while the shear modulus initially increases and then decreases. Notably, at room temperature, the elastic modulus, bulk modulus, and shear modulus of the composites increase with an increase in the degree of nanoparticle modification, while the Cauchy ratio exhibits the opposite trend. Our findings suggest that modified SiO2 nanoparticles have the potential to enhance the mechanical properties of composite materials. To validate our simulation results, we also conducted experiments that demonstrated the rationality of our approach.