▎ 摘　　要

Incorporation of functional nanofillers can unlock the potential of polymers as advanced materials. Herein, singlelayered and three-dimensional reduced graphene oxide (rGO)/ Ti(3)C(2)Tx (B-rGO@Ti(3)C(2)Tx) nanohybrids were constructed using bis(2-hydroxyethyl) terephthalate (BHET) as a coupling agent between rGO and Ti(3)C(2)Tx through covalent and hydrogen bonds. It is found that BHET can not only resist the weak oxidization of Ti(3)C(2)Tx to some degree but also prevent the self-stacking of Ti(3)C(2)Tx and rGO sheets. Then, B-rGO@Ti(3)C(2)Tx was used as a functional nanofiller and three-dimensional chain extender for preparing the waterborne polyurethane (WPU) nanocomposite through in situ polymerization. Compared with WPU nanocomposites with an equivalent amount of Ti(3)C(2)Tx/rGO@Ti(3)C(2)Tx, although containing an equivalent amount of BHET, WPU/B-rGO@Ti(3)C(2)Tx nanocomposites show significantly improved performance. For example, 5.66 wt % of B-rGO@Ti(3)C(2)Tx endows WPU with a high tensile strength of 36.0 MPa (improved by 380%), thermal conductivity of 0.697 W center dot m(-1)center dot K-1, electrical conductivity of 1.69 x 10(-2) S/m (enhanced by 39 times), good strainsensing behavior, electromagnetic interference (EMI)-shielding performance of 49.5 dB in the X-band, and excellent thermal stability. Therefore, the construction of rGO@Ti(3)C(2)Tx nanohybrids with the aid of chain extenders may unlock new possibilities of polyurethane as smart materials.