On the Mechanical Response of Silicon Dioxide Nanofiller Concentration on Fused Filament Fabrication 3D Printed Isotactic Polypropylene Nanocomposites.

Nectarios Vidakis,Markos Petousis,Lazaros Tzounis,Apostolos Korlos,Sotirios Grammatikos,Emmanouil Velidakis,Peder Erik Fischer-Griffiths,Nikolaos Mountakis

doi:10.3390/polym13122029

Abstract

Utilization of advanced engineering thermoplastic materials in fused filament fabrication (FFF) 3D printing process is critical in expanding additive manufacturing (AM) applications. Polypropylene (PP) is a widely used thermoplastic material, while silicon dioxide (SiO2) nanoparticles (NPs), which can be found in many living organisms, are commonly employed as fillers in polymers to improve their mechanical properties and processability. In this work, PP/SiO2 nanocomposite filaments at various concentrations were developed following a melt mixing extrusion process, and used for FFF 3D printing of specimens’ characterization according to international standards. Tensile, flexural, impact, microhardness, and dynamic mechanical analysis (DMA) tests were conducted to determine the effect of the nanofiller loading on the mechanical and viscoelastic properties of the polymer matrix. Scanning electron microscopy (SEM), Raman spectroscopy and atomic force microscopy (AFM) were performed for microstructural analysis, and finally melt flow index (MFI) tests were conducted to assess the melt rheological properties. An improvement in the mechanical performance was observed for silica loading up to 2.0 wt.%, while 4.0 wt.% was a potential threshold revealing processability challenges. Overall, PP/SiO2 nanocomposites could be ideal candidates for advanced 3D printing engineering applications towards structural plastic components with enhanced mechanical performance.

Highlights

Nanocomposite materials were fabricated in this work in four (4) different SiO2 filler concentrations (0.5 wt.%, 1.0 wt.%, 2.0 wt.% and 4.0 wt.%) and their properties were compared to pure PP
33 shows showsresults results obtained during the tensile tests
3a shows a typical stress to (MPa) to corresponding strainfor graph each material case a typical tensiletensile stress (MPa) corresponding strain graph each for material tested

Summary

Introduction

Fused filament fabrication (FFF) three-dimensional printing (3D printing) is one of the AM technologies that is currently widely employed, among others, in applications ranging from home use, up to prototyping and industrial manufacturing on a small scale [2]. Operational parts in wide range of machinery and applications, biomedical equipment, etc. A further feature of FFF technology is the ability to operate almost autonomously even up to 24 h per day and with little requirements regarding tools. This asset strengthens the ability of FFF equipment to operate even in non-industrial environments, leading to a more decentralized and flexible future production model [3]

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Conclusion