▎ 摘　　要

The epoxy-based nanocomposites are widely used in the aerospace field, which experience harsh conditions with extremely low and high temperatures. The temperature dependence of the properties of epoxy-based nanocomposites in a wide range of temperatures is of great importance for their application. In this work, we used the molecular dynamics (MD) simulation and experimental methods to comprehensively study the temperature dependence of epoxy-based nanocomposites. Three kinds of nanofillers, prepared by grafting three epoxy monomers with different functionality degrees to graphene oxide (GO), were used. The dynamic behavior, interfacial properties and mechanical properties of the nanocomposites in a wide range of temperatures were investigated by MD simulation. Simulation results showed that as temperature decreased from 600 to 4 K, all the nanocomposites exhibited decreased molecular mobility, increased interfacial interaction energy and increased Young's modulus. The tensile properties of the nanocomposites at room temperature (RT), liquid nitrogen temperature (LNT) and liquid helium temperature (LHeT) were also experimentally measured, which agreed well with the simulation results. The tensile strength of nanocomposites increased at LNT compared to that at RT, and then decreased at LHeT. Furthermore, the toughening mechanisms of EFGO to epoxy resin at different temperatures were discussed. The results are expected to provide a new insight into the design and preparation of nanocomposites applied at various temperatures.