Multiscale simulation on nonlinear mechanical properties of 3D printed cellulose composites

Abstract

Polypropylene (PP), a major thermoplastic resin, is widely used in compression molding and injection molding due to its excellent mechanical properties and recyclability. In general, talc, an inorganic mineral product, is widely used as a reinforcing filler in PP. Talc has excellent chemical stability, electrical insulation, and affinity with organic materials. However, PP has a high coefficient of linear expansion, making it difficult to use with the fused deposition modeling 3D printers that have become increasingly popular in recent years because of warping of the printed structures. On the other hand, cellulose nanofiber (CNF) is a plant fiber that has been degraded to the nanoscale and is expected to be used as a reinforcing filler for composite materials because of its superior specific stiffness and specific strength. It is expected to reduce environmental impact compared to conventional reinforcing fillers due to its reduced CO2 emissions and high recyclability. In addition, the high aspect ratio and low coefficient of linear expansion of CNF can be expected to reduce thermal deformation of composite materials. In this study, the mechanical properties of PP composites reinforced by talc and CNF fillers were tested by multiscale finite element analysis. The contents of talc and CNF were changed, and the effects of adding each were clarified.