Optimization course of hexagonal boron carbide ceramic nanofiller content in polypropylene for material extrusion additive manufacturing: Engineering response, nanostructure, and rheology insights

Polypropylene (PP) composites reinforced with hexagonal boron carbide (B₄C) nanoparticles were constructed using a Material Extrusion (MEX) 3D printing method. The goal was to provide nanocomposites for MEX 3D printing with enhanced mechanical properties by exploiting the superior properties of the B₄C additive. The fabricated 3D-printed specimens were subjected to standard evaluation tests to determine the effect of the B₄C nanofiller level inside the polymer framework on their mechanical, thermal, and rheological properties. The structures and fracture patterns of the filaments and specimens were inspected by electron microscopy. Raman spectroscopy and energy-dispersive spectroscopy were used to determine the chemical compositions of the nanocomposites. Comparing the unfilled polymeric matrix to the B₄C-filled nanocomposites reveals that the mechanical strength of the novel nanocomposite material was substantially increased. The optimum nanocomposite concentration of PP/ B₄C 6.0 wt% outperformed reference PP by 18.3%, 10.8%, 11.8%, and 15.6% in terms of flexural and impact strength, as well as tensile and flexural toughness, respectively, while having notably improved performance in the remaining mechanical properties. The nanocomposites presented herein can support applications that require polymeric materials with advanced mechanical properties.