Investigation of mechanical and electrical properties of photopolymer nanocomposites reinforced with carbon‐based nanoparticles produced by digital light processing <scp>3D</scp> printing technique

Abstract Digital Light Processing (DLP) techniques are being increasingly investigated to create advanced composite materials with improved properties by incorporating a variety of nanoparticles. In this study, the mechanical and electrical properties of photopolymer nanocomposite materials reinforced with carbon‐based nanoparticles produced by DLP were investigated. The nanocomposites were produced by incorporating varying proportions of Multi‐Walled Carbon Nanotubes (MWCNT), reduced Graphene Oxide (rGO), and combinations of Carbon Black and Carbon Nanotubes (CB/CNT) into the photopolymer matrix. The mechanical properties of the nanocomposites were assessed by tensile testing, while their electrical conductivity was determined using the four‐point probe technique. This study was the first to investigate the most effective concentrations of three distinct carbon‐based nanoparticles and the impact of their homogeneous distribution on the performance of composites with a holistic approach. The morphological analysis of the composites, conducted using optical microscopy and Scanning Electron Microscopy (SEM), revealed the critical role of nanoparticle distribution in determining composite properties. The findings indicate that the incorporation of nanoparticles at low proportions (up to 0.5 wt%) resulted in a significant improvement, with up to an 82% increase in the ultimate tensile strength of the photopolymer. Nevertheless, as the nanoparticle ratio increased, a rise in material brittleness and a decrease in mechanical strength were observed. On the other hand, electrical conductivity showed a significant increase when the percolation threshold was exceeded in the composites reinforced with MWCNT (0.5%wt) and CB/CNT (0.75%wt). Highlights The properties of DLP composites with carbon nanoparticles are investigated. SEM analysis shows nanoparticle dispersion's key role in composite performance. 0.5% rGO reinforcement boosts tensile strength by up to 82%. Conductivity surges at 0.5% MWCNT, surpassing the percolation threshold. High nanoparticle ratios increase composite brittleness.