Optimizing the SLS process parameters for enhancement of mechanical,thermal and rheological properties in a new PLA/EPDM/TiO 2 /CNT nanocomposite

Abstract

In the present study, a new Polylactic acid/Ethylene Propylene Diene Monomer/Titanium dioxide/Carbon nanotubes (PLA/EPDM/TiO₂/CNTs) nanocomposite was fabricated via selective laser sintering (SLS) to enhance its thermal stability, rheological behavior, yield strength, and elongation. The optimization process utilized response surface methodology (RSM) and desirability function analysis (DFA), focusing on the critical parameters of laser power, scan rate, and the content of CNTs and TiO₂ nanoparticles. The thermal, rheological, and microstructural properties were characterized using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) imaging, and frequency sweep tests. An enhancement in the thermal stability of the nanocomposite was observed upon the incorporation of CNT and TiO₂ nanoparticles. Effective nanoparticle dispersion was confirmed by microstructural and rheological measurements at 2 wt% CNT and 2 wt% TiO₂. The optimal parameters for concurrent improvement of yield strength and elongation, as determined by RSM and DFA, were established to be 1.6 wt% CNT, 1.8 wt% TiO₂, a scan rate of 2740 mm/s, and a laser power of 17.15 W.