EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Acrylonitrile-butadiene-styrene (ABS) is currently one of the most used polymeric materials in fused filament fabrication (FFF) for industrial applications, due to its good mechanical properties and good range of operating temperatures. However, materials printed via FFF present high anisotropy in the mechanical properties due to poor adhesion between the printed layers. This may lead to a decrease below 1/3 in tensile strength. Moreover, adequate 3D printing of ABS requires the previous heating of a printing platform or chamber above 90 ºC to ensure good adhesion of the first deposited layer and minimize undesired effects as warping.
In this work we present a set of materials suitable for FFF prepared from blends containing ABS and thermoplastic polyurethane (TPU). Printing conditions were optimized for ABS:TPU blends containing 10-30 wt% TPU. FTIR, Raman and AFM analyses showed good compatibility between ABS and TPU, evidenced by the presence of new hydrogen bonding interactions and absence of phase macro-separation between these two compounds. Mechanical properties were studied using 3D-printing normalized test specimens printed in different directions. It was observed that blends containing 10 – 20 wt% TPU led to enhanced adhesion between layers without significant loss in yield strength, when compared to pure ABS. Furthermore, blends containing 30 wt% TPU allowed successful fabrication of objects without heating the printing platform. Mechanical properties of this material did not vary when the printing platform was increased up to 90 ºC.