Synthesis and Characterization of Graphene-Reinforced Polymer Filaments for Additive Manufacturing

Abstract

Fused Deposition Modeling (FDM) is a popular 3D printing process which uses a spool of thermoplastic polymer filament that is melted by the movable extruder printer head onto the bed to generate the required shape. The most used polymer filaments in FDM are Acrylonitrile Butadiene Styrene (ABS) and Poly Lactic Acid (PLA). However, these conventional polymer filaments have lower mechanical strength and are more susceptible to cracking as the cooler parts of the printed part shrink so much that they cause cracks to develop, leading to warping. The current investigation focuses on the synthesis of graphene, synthesis of polymer filaments and characterization techniques for further development of graphene reinforced polymer filaments. Graphene is made from a single layer of carbon atoms arranged in a hexagonal lattice. The improved thermal transport properties provided by graphene to the polymer will lead to a lower heat differential between layers being printed and prevent warping from occurring. The high strength to weight ratio of graphene will lead to the formation of mechanically stronger 3D printed parts. The synthesis of graphene carried out in the lab led to the development of successful batches of functionalized graphene that can be used in the development of graphene reinforced polymer filaments. With the Determination of the relationship of parameters between the extruder and the winding unit, spools of uniform diameter filaments can be developed for usage. The characterization techniques developed over the course of this study prove to be accurate for the measurement of tensile strength and thermal conductivity of polymer filaments. These characterization techniques can be used for the evaluation of tensile strength and thermal conductivity of graphene-reinforced polymer filaments to show the changes developed by the introduction of graphene.