▎ 摘　　要

Aminated polyethylene glycol (PEG-NH2) functionalized graphene nanosheets (PEG-rG) were successfully introduced into epoxy resin as a core-shell nanostructure to prepare the epoxy based dielectric composite. The overall mechanical and dielectric performances of the PEG-rG/epoxy nanocomposites were greatly improved in comparison with its counterparts employing with untreated graphene. The dielectric constant of PEG-rG/epoxy 1.5 wt% nanocomposites reached 84.3 at 100 Hz, two times higher than that of rG/epoxy 1.5 wt% system. What's more, the dielectric loss is effectively reduced to a very low level (tan delta = 0.21). (C) 2019 Elsevier B.V. All rights reserved.