304 / 2022-03-15 10:30:26

Molecular dynamics simulation of microstructure of bisphenol-A functionalized nano graphene oxide / epoxy resin composites

Epoxy nanocomposites,graphene oxide,grafting modification,molecular dynamics

Epoxy nanocomposites, as a research hotspot in the field of dielectrics, have excellent thermodynamic and electrical properties. Nano graphene oxide (NGO) is a two-dimensional layered nanofiller. Compared with traditional nanofillers such as Al₂O₃ and SiO₂, NGO has the characteristics of a large surface area and more oxygen-containing polar functional groups. However, due to its large surface energy, NGO is prone to "aggregation" and affects the compatibility of nanofillers in the matrix. As a method to improve the compatibility of nanofillers, the effect of nanofiller grafting modification on the microstructure of epoxy composites is still less studied. Based on the above reasons, the molecular models of bisphenol-A functionalized graphene oxide(f-DGEBA-GO), NGO, and pure epoxy nanocomposite models are established based on molecular dynamics, and this paper studies the effects of NGO grafting modification on the microstructure of the composites. It is found that when the nanofiller is a low mass fraction, the cohesive energy density of the model is higher and the compatibility between the nanofiller and the matrix is better, but the compatibility decreases with the increase of mass fraction; The rigidity of the molecular chain in the f-DGEBA-GO nanocomposite model is enhanced, the interaction between the nanofiller and the matrix is improved, and the mean square displacement of the nanofiller is effectively restrained, to improve the compatibility of f-DGEBA-GO in the matrix.