Toward Sustainable 3D Printing: Tensile Mechanical Comparison of PLA/PBAT Biopolymer Blend and TPU in MEX Additive Manufacturing

A biopolymer blend of poly(lactic acid) (PLA) and poly(butylene adipate-<i>co</i>-terephtalate) (PBAT) in a 60/40 weight ratio was investigated as a potential green alternative to thermoplastic polyurethane (TPU) for material extrusion (MEX)-based additive manufacturing. A comparison of the two materials was conducted based on their tensile mechanical properties, evaluated using 3D-printed specimens fabricated with three distinct infill raster orientations (0°, ±45°, and 90°). The results showed that the tensile strengths of the two materials were relatively similar, ranging from 14.7 to 34.8 MPa, depending on the raster angle. However, the stiffness of PLA/PBAT was considerably higher than that of TPU, as reflected by Young’s modulus values an order of magnitude greater. While the elongation at break was comparable at 0° infill orientation (214% for PLA/PBAT and 265% for TPU), TPU exhibited better tolerance to increasing raster angles, with elongation only decreasing to 134% at 90°. In contrast, PLA/PBAT dropped drastically to 2%.