Influence of the Functional Composition of the Surface of Carbon Nanofillers on the Physical and Mechanical Properties of Thermoelastoplastic Elastomers Developed for 3D Printing

When developing a material for 3D printing, thermoplastic behavior alone of the polymer is not sufficient; appropriate rheological characteristics are also required that allow the material to be easily extruded through a thin nozzle of a 3D printer. In this study, a composition based on a styrene–butadiene thermoplastic elastomer with rheological properties that allow the fabrication of products on a 3D printer is investigated. The influence of the ratio between the components of a mixed nanocarbon filler, including graphene and carbon nanotubes, and the distribution of adsorption centers on their surface on the physical and mechanical characteristics of a thermoplastic elastomer (TPE) based on a styrene–butadiene elastomer is studied. The optimal ratio between graphene and nanotubes is determined to be 1 : 3, which provides the maximum increase in tensile and compressive strength due to the combination of the reinforcing action of one-dimensional nanotubes and the interaction of two-dimensional graphene layers with the polymer matrix. It is established that the strengthening of the resulting compounds is correlated with the content of the Brønsted basic centers (BBCs) on the filler surface, characteristic of graphene and presumably corresponding to peroxide groups that promote cross-linking of the polymer matrix.