4D Printing of PLA/PBS Biopolymers: Impact of Polymer Grade Variations on Thermomechanical Performance

The adoption of biobased polymers is growing in the additive manufacturing industry, offering alternatives to petrochemical-based plastics, known for their environmental impact. However, finding a single polymer with all desirable properties is challenging. Blending polymers allows for the combination of distinct features, optimizing performance for specific applications. This study formulates two biopolymer blends of poly(butylene succinate) (PBS) and poly(lactic acid) (PLA) (80/20 wt%) using different PBS grades to examine their effects on thermomechanical and functional properties. The addition of PLA, a shape memory polymer, enables dynamic changes in 3D printed structures, causing them to deform under stimuli and revert to their original shape—an effect known as 4D printing. The blend pellets are then used in filament extrusion, and smart sandwich samples are produced using fused filament fabrication. The thermomechanical and functional characteristics of the printed samples are evaluated. This research highlights the differences arising from using different PBS grades in 3D printed structures with high energy absorption. Results show that melt flow rate is a crucial factor, significantly affecting the thermomechanical and shape memory behavior, with variation between 86% and 93%.