Creation of an electrically conductive composite with polymer materials for 3D-printing based on surface modification

The study addresses the problem of imparting electrical conductivity to conventional polymer materials for 3D printing by means of surface modification. Polylactide, polyethylene terephthalate glycol, and thermoplastic polyurethane were used as the polymer matrices. The conductive polymer complex poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) was applied as a surface modifier. The modification procedure consisted of impregnating polymer samples with an aqueous PEDOT:PSS dispersion followed by thermal treatment. Electrical properties of the obtained composites were evaluated by measuring resistance and calculating specific electrical conductivity. Surface modification was shown to increase the conductivity of the polymers by 12–14 orders of magnitude compared to the initial dielectric materials. The highest specific conductivity was achieved for the polyethylene terephthalate glycol + PEDOT:PSS composite and reached 9.26×10^-2 S/m. The conductivity of the polylactide-based composite was 2.73×10^-3 S/m, while thermoplastic polyurethane exhibited the lowest value of 3.97×10^-6 S/m, which is attributed to the structural features and reduced wettability of the elastomer surface. Optimal processing parameters were established as 30 minutes of ultrasonic treatment and a drying temperature of 100 ℃. Dispersion dilution with water was found to reduce electrical conductivity, whereas the addition of organic solvents to the modifier was ineffective. A synergistic effect was revealed when combining bulk filling of polylactide with multiwalled carbon nanotubes and subsequent surface modification with PEDOT:PSS, with maximum conductivity observed at a nanotube content of 7 %. The results demonstrate the practical potential of the proposed method for manufacturing electrically conductive functional components using additive manufacturing technologies.