A Polymer Science Perspective on Improving Additive Manufacturing*

3-D printing of polymers has become an important manufacturing process in industry and among hobbyists. This process, however, results in significantly weak interfaces between filaments and between layers. These weak interfaces manifest in anisotropic properties, where the sample is stronger parallel to the print direction than perpendicular to it. Our research is focused on cultivating methods to understand the adhesion between layers on a molecular level and develop materials and processes to optimize this bonding process and structural robustness.
We have therefore embarked on a holistic research program that will address these concerns by developing a fundamental understanding of reactive and physical processes that occur during the FDM process from a polymer science perspective. These projects include the incorporation of reactive processing in extrusion based polymeric 3D printing, the integration of surface segregating additives to the base filament to bias stronger interfaces, the addition of graphene into filament to optimize thermal transport during the printing process, and applying dynamic covalent bonds in the 3D printed materials to develop self-healing 3D printed parts.