4D Printing With Polylactic Acid/Polyethylene Terephthalate Glycol Polymer Blends: An Assessment of Printability, Thermal Properties, Mechanical Properties, and Shape Memory Performance

ABSTRACT The polymer blending method is the most widely used to improve the structural performance and mechanical properties in many applications. In this study, shape memory polymer blends were produced from polylactic acid (PLA) with three weight percentages of 20%, 50%, and 80% which were used to enhance the properties of polyethylene terephthalate glycol (PETG), and these blends were successfully 4D printed. The PLA and PETG are melt‐mixed to produce filaments appropriate for 3D/4D printing. Differential Scanning Calorimetry revealed multiple glass transition temperatures, suggesting their immiscibility. The effects of raster angles, such as 0°, 45°, and 90°, on the shape memory and mechanical performance of 3D printed PLA/PETG blends were investigated. The highest tensile and flexural strengths were observed for the PLA80/PETG20 blends, with the best performance observed for the 0° raster angle. The PLA80/PETG20 blend exhibited superior mechanical performance compared to neat PLA, exhibiting variations of −0.7% in tensile strength, +2.6% in flexural strength, and +14.4% in compressive strength. Relative to PETG, the blend exhibited major improvements of +14.3% in tensile, +27.3% in flexural, and +43.4% in compressive strength. Furthermore, specimens printed at 0° exhibited the highest fixity (97.6%), while those printed at 90° showed the highest recovery (97.4%).