Carbon Nanotubes-Polyurethane Vitrimer Nanocomposites with the Ability of Surface Welding Controlled by Heat and Near-Infrared Light

Welding technology of polymer materials, serving as an exceedingly good tactics to save materials, reduce cost, and reduce material loss, is only extensively applied in thermoplastic materials for the moment. Recently, a new class of polymer, known as vitrimer, has attracted the eye of researchers because it realizes the reprocessing and reshape of thermosets and possesses many excellent functions, such as multishape memory, healing, and surface welding. Among these, the vitrimer makes the surface welding of thermosetting material possible. In this paper, carbon nanotubes-polyurethane vitrimer nanocomposites with the capability of surface welding controlled by heat and near-infrared (NIR) light are successfully prepared. Here, the effects of surface welding are characterized by lap shear tests and optical microscope. In addition, from the control experiments, it is found that the shear strength of the light-welding sample under NIR illumination for 1 min is greater than that of the heat-welding sample at 110 °C for 10 min. Furthermore, thermosetting polyurethane has been applied in many fields, and it is hoped that the findings, especially near-infrared welding technology, will make some contributions for welding technology of polymer.