Creep performance of CNT-based nanocomposites: A parametric study

Epoxy materials have been widely applied in various applications ranging from nanoscale structures, such as microelectronic devices, to macroscale components in aerospace and building constructions. The structural stability under constant loadings is a major concern for polymeric materials during long-term service. The incorporation of carbon nanotubes (CNTs) into epoxy matrix has been considered to enhance creep resistance in recent decades. Substantial improvement of CNT-based nanocomposites largely relies on optimized design of material microstructures, and such manipulation requires comprehensive understanding of creep behavior in CNT-epoxy nanocomposites. In addition, effective arrangement of CNTs in epoxy matrix for enhancement in creep resistance needs a systematic study of related parametric effects. In this work, the effects of CNT length, CNT weight fraction and CNT dispersion state on the creep response of nanocomposites are investigated using molecular dynamics simulations. The creep deformation of nanocomposites including creep strain and system dynamics are found to decrease with the increasing length, weight fraction and good dispersion state, showing the contribution of the additional CNTs towards the resistance in time-dependent deformation. These results suggest that the CNT-epoxy nanocomposites with superior creep resistance can be achieved in the design by optimizing the CNT-associated parameters.