polymeric nanocomposites with improved mechanical, flame retardant, and electromagnetic shielding properties by various approaches has been developed. [15-20] Yu et al. [17] modified the exfoliated Ti3C2 in aqueous solution by using two kinds of cationic modifiers, i.e., cetyltrimethyl ammonium bromide and tetrabutyl phosphine chloride, and studied fire safety properties and flame-retardant mechanism of MXene/TPU nanocomposites. Thermoplastic polyurethane (TPU) is one of the most commonly used elastomers, and it is a multisegmented copoly mer composed of hard segments and soft segments. [21] Due to excellent abrasion resistance, processability, transparency, recyclability, and mechanical performance, TPU is widely used in automobiles, medical devices, tubes, sporting goods, and decorations. However, its low stiffness, thermal conductivity, and tensile strength may limit its application in some fields. To solve these problems, many researchers prepared TPU-based composites by adding rigid functional materials into the TPU matrix. [22-24] Moreover, the polyethylene glycol (PEG) possessing high affinity with MXene. [25-27] Bera and Maji [24] prepared the graphene/TPU nanocomposites by in-situ solution poly merization technique and studied their mechanical properties, the results demonstrated that the tensile strength of the synthesized nanocomposite was increased by 280% and the toughness was increased by 410% after adding 0.10 wt% graphene oxide. Ning et al. [27] prepared the TPU/ PEG/rGO nanocomposites via melt blending method, and the results showed that there was a great interaction between MXene and the matrix after adding PEG. Rheology is a discipline that studies the deformation and flow of materials under the action of applied stress. The formation of internal network structure, filler dispersion, and interface interaction between filler and polymer matrix can be demonstrated by studying the change of modulus and viscosity. [28-34] Therefore, investigating the rheological properties of TPU/MXene composites is of great significance for evaluating the effect of MXene on the internal structure of composites. To our knowledge, the effects of different MXene content on mechanical, thermal, and rheological properties of TPU composites are rare in the open literature, [18] and we studied the rheological properties of MXene-based composites by melt rheology tests for the first time. In this work, we prepared Ti 3 C 2 T x MXene nanosheets by chemical etching Al atom layer from the layered Ti 3 AlC 2 MAX phase, then pretreated the Ti 3 C 2 T x MXene nanosheets with PEG by solution blending, and Ti 3 C 2 T x MXene/TPU nanocomposites were prepared via melt blending and compression molding. Finally, the mechanical properties, In this work, a novel nanocomposite is prepared via a melt blending of thermoplastic polyurethane (TPU) and Ti 3 C 2 T x MXene nanosheets pretreated with polyethylene glycol. It is found that the tensile strength and elongation at break increased by 41.2% and 15.4% at MXene loading values of 0.5 wt%...
