3D-printed nanocomposites filled with untreated and surface-modified PTFE powders treated by a Na-naphthalene-system

This study focuses on the mechanical properties of DLP/LCD-type 3D-printed nanocomposites comprised of polyester acrylate resin with DPGDA reactive diluent filled with untreated PTFE and surface-modified PTFE powders by the Na-Naphtalenide system. To obtain the nanocomposites, untreated and surface-modified PTFE powders were incorporated into the resin systems at loading ratios ranging from 1% to 6%. The X-ray photoelectron spectroscopy (XPS) data following the Na-naphthalene system treatment demonstrated the existence of functional groups such as OH, carbonyl, and C=C unsaturation groups on the surface of the untreated PTFE powders. The study showed improvements for the nanocomposites obtained through a DLP/LCD type 3D printer up to a certain ratio in terms of tensile strength, Young's modulus, Izod impact resistance, and Shore D hardness values. Evaluating the promising samples, the nanocomposites with surface-modified PTFE powders of 2% and 1% showed increases of 5.1% and 7.6% in ultimate tensile strength and Izod impact resistance compared to the unfilled polyester acrylate sample. On the other hand, the nanocomposite with untreated PTFE powders of 1% only showed increases of 2.4% and 3.2% in ultimate tensile strength and Izod impact resistance. Moreover, Young’s modulus showed less decrease for surface-modified PTFE-filled nanocomposites.