High content filling, toughness, and conductive performance of thermoplastic polyurethane/carbon nanotubes composites prepared by constructing the compact interface

Conductive polymer composites have drawn significant attentions. However, the low interface between nanomaterials and polymer matrix may result in the failure of function during the applications. Herein, we report a simple, effective, and scalable strategy for the fabrication of thermoplastic polyurethane (TPU)/carbon nanotube (CNT) composites with high content filling, good interfaces, and high toughness. The distribution of CNT in the TPU matrix was well regulated using a binary-solvent assisted non-solvent induced phase separation method to solve the interface problem. The results showed that the hydrogen-bonding was beneficial to the construction of a good interface, and the thermal stabilities of the polyurethane/carbon nanotubes composite films (PCCFs) were significantly improved. Most importantly, the as-prepared PCCF with 25% CNT exhibited a tensile stress of 20.3 ± 1.7 MPa, a strain of 1084.7 ± 206.9%, and toughness of 171.9 ± 39.8 MJ m−3, respectively, mainly ascribed to a microcrack, a CNT bridge, CNT orientation, and pulled-out CNT. The flexible films also showed good conductivity under strain of 0–200%. These findings suggested that the technique described herein is broadly applicable in the design and fabrication of a new kind of conductive and tough composites.