Correlation between mechanical dissipation and improved X-band electromagnetic shielding capabilities of amine functionalized graphene/thermoplastic polyurethane composites

•Thermally reduced graphene oxide was modified by grafting 2-aminoethyl methacrylate.•Polymer nanocomposites of TPU/TRGO and TPU/mTRGO were prepared by solution mixing.•The graphene modification enhances interfacial interactions and mechanical damping.•The TPU/mTRGO5 with 1mm thickness attenuates 99.7% of emitted electromagnetic waves.•The shielding via absorption can be influenced by viscoelastic energy dissipation.