Comprehensive investigation of a novel PLA/EPDM/TiO 2 /CNT nanocomposite produced by selective laser sintering

Abstract

This study aims to enhance the electrical, mechanical, and thermal properties of a novel PLA/EPDM/TiO₂/CNT nanocomposite fabricated by selective laser sintering (SLS). For this purpose, the response surface method (RSM) was employed to examine the effect of the process parameters such as laser power, scan rate, CNTs, and TiO₂ nanoparticles on the melting temperature, crystallization temperature, electrical conductivity, tensile stress, and impact resistance of the nanocomposite. Thermal characterization was conducted via TGA and DSC, whereas electrical and microstructural properties were assessed using a four-probe test and SEM imaging. The results indicate that incorporating CNT and TiO₂ nanoparticles significantly enhanced the material’s thermal stability and electrical conductivity. A homogeneous distribution of nanoparticles within the microstructure was achieved with a 2 wt% concentration of CNT and TiO₂. Furthermore, minimal porosity and effective solidification were obtained at a laser power of 18 W and a scan rate of 2500 mm/s. The optimization process using RSM and desirability function analysis determined that the optimal parameters for simultaneously improving tensile stress and impact resistance were: 1.8 wt% CNT, 1.9 wt% TiO₂, a laser power of 16.5 W, and a scan rate of 2624 mm/s.