▎ 摘　　要

As the application environment of electromagnetic interference (EMI) shielding composites becomes increasingly complex and changeful, the polymer materials with excellent mechanical properties and EMI shielding effec-tiveness (EMI SE) are highly desired, in order to maintain the long-term operation of equipment. Herein, we report a series of flexible and self-healing EMI shielding composites, which are developed by first constructing a highly electrically conductive 3D porous Ti3C2Tx MXene/reduced graphene oxide (rGO) hybrid aerogel (MRG) by the freeze-drying and chemical reduction methods, and subsequently introducing dynamic crosslinked poly-urethane containing Diels-Alder bonds (PUDA) into MRG by the vacuum assisted impregnation method. The 3D MXene/rGO/PUDA (MRGP) composites show a high EMI SE of 39.1 dB at an ultra-low 0.46 vol% of MXene and 0.65 vol% of rGO loading in the range of X-band (8.2-12.4 GHz), and the EMI SE can recover to 34.1 dB after three times of severing/healing cycles, retaining 91.4% of the EMI SE of the initial sample. In addition, the EMI SE of thrice healed MRGP composite hardly changes after 5000 bending cycles. The flexible and self-healing EMI shielding PUDA composites in our work show great potential application for long-term protection of portable communication electronic equipment.