▎ 摘　　要

While the subject of creep and recovery in polymers is not new, its temperature dependence in graphene-polymer nanocomposites is. In such nanocomposites, the interface activity plays a critical role that is absent in a pure polymer phase. Several recent experiments have also demonstrated the remarkable impact of temperature in such nanocomposites, but at present no theory seems to exist to predict the observed data. The issue is even more complicated when filler agglomeration is present. To achieve this goal, we invoke a two-scale agglomerate-based homogenization scheme to address the issue of filler agglomeration and a thermodynamically driven temperature-degraded process to describe the interface effect. Time-temperature superposition principle with a reduced time scale is also employed for the polymer matrix. Several key microstructural features including graphene volume concentration, aspect ratio, and dispersion state of nanofillers in the graphene-rich agglomerates and the graphene-poor matrix are all considered. The theory is developed in the Laplace transformed space. It is shown that the predicted creep strain of a graphene/polystyrene nanocomposite is significantly enhanced with the increase of temperature, but its recovery strain remains relatively flat. Graphene loading notably decreases the overall creep, but filler agglomeration and temperature-degraded process both greatly enhance it. The calculated results are all in close agreement with experiments. This work could provide guidance for tailoring creep and recovery properties of graphene nanocomposites by temperature.