▎ 摘　　要

Graphene/polymer nanocomposites have attracted much attention due to their variability and flexibility. In this paper, graphene/polyvinylidene fluoride (graphene/PVDF) and graphene/Thermoplastic polyurethanes (TPU)-PVDF nanocomposites were successfully prepared by the combined action of viscoelastic matching of polymer and impaction shear field of high-energy ball milling, and the effects of four technological parameters on the exfoliation effect of expanded graphite were investigated. The interlayer exfoliation and graphenization of graphite were realized during the ball milling process. XRD, Raman spectroscopy, SEM, TEM, AFM, conductivity test, and electromagnetic shielding effectiveness were used to characterize the structure and performance of the composite. The results show that the graphene thickness in nanocomposites is about 4-7 layers. When the mass fraction of EG is 6%, the conductivity of the composite reaches 0.41 S/m, and the electromagnetic shielding effectiveness (EMSE) reaches 15.8 dB. Ball milling together with EG-TPU-PVDF as a grinding agent can effectively realize graphenization of graphite. When the mass fraction of TPU with 44% of hard segment ratio is 10%, graphene thickness in graphene/TPU-PVDF nanocomposites is about 3-5 layers. When the mass fraction of EG is 6%, the electrical conductivity is 1.01 S/m, and the EMSE is 21.4 dB, which shows that the graphene/TPU-PVDF nanocomposites is a typical absorbing type of electromagnetic shielding material.