Effect of nanosized carbon black content on the microstructure, thermal stability, and mechanical properties of 3D printed poly urethane acrylate

The stereolithography method (SLA) is a rapid prototyping method, which can produce complex geometric shapes within the shortest time as compared to conventional manufacturing. The strength of the samples printed via this method is a significant problem for its wide application. Adding an additive can improve the photopolymer substrate properties. In this research, carbon black nanoparticles at 0.1, 0.3, 0.5, and 1 wt% were dispersed inside a urethane acrylate photopolymer using a mechanical stirrer. The nanocomposites were printed in a stereolithography device with a suitable viscosity. The results indicated that the nanocomposite sample containing 0.1 wt% carbon black showed a tensile strength of 16 MPa, and the virgin resin sample revealed a strength of 8 MPa. Elongation to break the pure resin and nanocomposite containing 0.1 wt% of carbon black was 6.36 and 7.17, respectively. Also, the hardness of the samples increased with the elevation of the carbon black content; in the presence of 0.3 and 0.5 % of carbon black, the sample hardness increased from 79 to 83 Shore D as compared to the pure sample. The thermal stability or degradation temperature increased from 316 °C for the pure resin to 343 °C for the nanocomposite containing 0.1 % carbon black; with a further elevation of the carbon black content, the degradation temperature diminished.