Morphological, thermal, and mechanical properties of 4D-printed ABS/TPU blends for thermoresponsive shape memory applications

This study investigated the shape memory effect of a four-dimensional (4D) printed acrylonitrile-butadiene-styrene/thermoplastic polyurethane (ABS/TPU) blend for use in fused deposition modeling (FDM) three-dimensional (3D) printing. The composite polymer filament was formed by blending ABS and TPU using a single-screw filament extruder at ABS/TPU mass ratios of 40/60, 50/50, 60/40, 70/30, 80/20, and 90/10. These filaments were used in FDM 3D printing to produce shape memory polymers (SMPs). The thermal and mechanical properties of the printed SMPs with various mass ratios were analyzed. An ABS/TPU blend with a mass ratio of 50/50 was selected as a preliminary example for testing shape memory effects. Therefore, it is also straightforward to manufacture. Thermogravimetric analysis and differential scanning calorimetry revealed that it exhibited improvement in thermal properties, where T d was 1% of 277.5 °C, T g was 103.8 °C, T c was 135.3 °C, and T m2 was 235.0 °C. A dynamic mechanical analysis showed that the storage modulus, loss modulus, and dynamic damping factor of the ABS/TPU composite all improved. The tensile test results showed that the energy absorption rate, storage modulus, and shape fixity of the composites were enhanced by the tensile strength of ABS, whereas the elongation at break and shape recovery ability of the composites were increased by the elastic recovery behavior of TPU.