Bis(2-hydroxyethyl) Terephthalate-Modified Ti₃C₂T/Graphene Nanohybrids as Three-Dimensional Functional Chain...

Incorporation of functional nanofillers can unlock the potential of polymers as advanced materials. Herein, single-layered and three-dimensional reduced graphene oxide (rGO)/Ti₃C₂T (B-rGO@Ti₃C₂T) nanohybrids were constructed using bis(2-hydroxyethyl) terephthalate (BHET) as a coupling agent between rGO and Ti₃C₂T through covalent and hydrogen bonds. It is found that BHET can not only resist the weak oxidization of Ti₃C₂T to some degree but also prevent the self-stacking of Ti₃C₂T and rGO sheets. Then, B-rGO@Ti₃C₂T 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 Ti₃C₂T/rGO@Ti₃C₂T, although containing an equivalent amount of BHET, WPU/B-rGO@Ti₃C₂T nanocomposites show significantly improved performance. For example, 5.66 wt % of B-rGO@Ti₃C₂T endows WPU with a high tensile strength of 36.0 MPa (improved by 380%), thermal conductivity of 0.697 W·m^-1·K^-1, electrical conductivity of 1.69 × 10^-2 S/m (enhanced by 39 times), good strain-sensing behavior, electromagnetic interference (EMI)-shielding performance of 49.5 dB in the X-band, and excellent thermal stability. Therefore, the construction of rGO@Ti₃C₂T nanohybrids with the aid of chain extenders may unlock new possibilities of polyurethane as smart materials.