Inorganic Fullerene-Like WS2 Reinforced Polyamide Powders for Improved Mechanical Properties in Laser Sintered Nanocomposite Parts

Abstract

Polyamide (PA) is a widely utilized engineering polymer, and its thermal and mechanical properties can be further improved by adding nanofillers. However, adding inorganic fullerene-like tungsten disulfide (IF-WS2) nanoparticles (NPs) to PA to produce composite precursor powders for additive manufacturing is challenging. Here, we report a novel and cost-effective method for fabricating PA-12 based nanocomposite (NC) powders with fixed/partially encapsulated IF-WS2 nanoparticulate fillers utilizing an advanced mixing technique because simple wet mixing (WM) can only attach fillers weakly to the powder surfaces when compared to the proposed method. The resulting nanocomposite powders maintained nearly the original particle size distribution of PA-12. They also exhibited improved rheological properties, melting, and crystallization behaviors compared with those prepared by the WM method. The laser-sintered PA-12 nanocomposite specimens revealed enhanced powder thermal stability and higher tensile strengths than pristine PA-12, validating the advantages of the novel technique for the fabrication of polyamide nanocomposite powders and their suitability for utilization in laser sintering additive manufacturing. These results demonstrate that high-performance engineered PA-12 nanocomposite components can be directly laser sintered, and this technique can potentially be extended to fabricate other engineered polymeric nanocomposite powders.