Flexural property characterization and structure analysis of graphene‐reinforced polyphenylene sulfide prepared via low‐cost pellet‐based material extrusion additive manufacturing

Abstract This paper proposed a low‐cost and high‐efficient method incorporating the graphene nanoplatelets (GNPs) into polyphenylene sulfide (PPS) as the feedstock of the pellet‐based material extrusion additive manufacturing (pMEAM). GNP/PPS particles with varying mass fractions are pre‐mixed by a mechanical mixer and then directly processed through a low‐cost screw‐based pMEAM system. The mechanical flexural properties of the samples are measured. The differential scanning calorimetry and thermogravimetric analysis are performed to explore the thermal‐related behavior of the samples. The optical microscopy and scanning electron microscopy are used for the characterization of the microstructures of the samples. The results indicate that the addition of GNP enhances the mechanical properties and thermal stability of PPS and GNP/PPS composites. Specifically, the flexural strength and modulus of the 0.05 wt.% GNP/PPS composite material increased by 21.7% and 17.5%, respectively. Nevertheless, an excessive amount of GNP can lead to decreased bending strength and other unstable mechanical properties. Microstructures of the prepared samples show that an increased fraction of graphene nanofillers reduces the hardness of the composites. Overall, the GNP/PPS prepared via our low‐cost pMEAM method exhibits a promising mechanical performance and can be further applied to large‐scale engineering applications for rapid productions. Highlights A low‐cost and efficient method is employed to rapidly prototype GNP/PPS composites, employing a combination of pellet‐based material extrusion additive manufacturing and high‐speed mechanical mixing. The mechanical and thermal properties of the GNP/PPS composites are notably improved by the addition of GNP fillers, resulting in increased flexural strength and stiffness, and higher material crystallinity. Micro‐ and meso‐structural analysis reveals the uniform dispersion of graphene fillers in the interlayers, which potentially contributes to the improved mechanical properties, despite the presence of inherent micro‐voids. Owing to the extensive functionalities of GNP, the proposed method offers a promising and viable alternative for the rapid fabrication of industrial parts and tooling on a large scale.