Molecular Dynamics Study on the Effect of Silicon Carbide Nanoparticles on Mechanical and Thermal Properties of an Araldite Epoxy Resin

Epoxy resins are thermoset polymers with extensive industrial applications. Their superior properties have attracted great attention in different fields. Having the potential to provide enhanced strength-to-weight and stiffness-to-weight ratios, reinforced polymers are superior to unreinforced ones. Using nanoparticles as reinforcement in a polymer can improve toughness, aging resistance, strength and fracture of the composites.

Molecular dynamics method was used to study the effects of silicon carbide (SiC) nanoparticles on the mechanical and thermal properties of the Araldite LY 5052/Aradur HY 5052 epoxy resin. Different simulation phases, including the minimization, equilibration, curing, and calculation of mechanical properties were carried out by NPT and NVT ensembles, based on the COMPASS II force field.

The simulation results indicated that the mechanical properties of the epoxy resin system at 300 K were not only in good agreement with other experimental and theoretical properties, but also they produced greater accuracy than the previous work by COMPASS force field. The results also indicated that the addition of SiC reinforcement to the epoxy resin system improved the mechanical properties such as strength and hardness as well as the thermal properties of the system while its density increased slightly. They showed that the optimum mechanical properties were related to low concentration of SiC nanoparticles. In epoxy resin with a higher nanoparticles percentage, by increasing the weight percentage, an agglomeration phenomenon occurred, porosity increased, and consequently the mechanical and thermal properties decreased. The effect of particle size on the mechanical and thermal properties of the epoxy resin system also showed that by increasing the particle size, the mechanical and thermal properties of the system were reduced. SiC nanoparticles with 3 different nanoparticle geometries were added to the epoxy resin system. The results showed that, due to a higher surface-to-volume ratio (0.6 1/cm), the epoxy resin system with the spherical reinforcement presented higher mechanical properties than the cylindrical (0.5 1/cm) and planar (0.26 1/cm) reinforcements.