Tailor-made 3D printing TPU/PLA composites for damping and energy absorption

• Developed 3D printing TPU/PLA composite filaments with enhanced damping and stiffness properties. • Achieved a damping peak value of 0.603 at room temperature and an effective damping temperature range exceeding 100 °C. • Printed a lattice structure resembling Kelvin foam demonstrating superior energy absorption performance. • Provided a new method for the application of damping materials in the field of 3D printing. Commercially available thermoplastic polyurethane (TPU) materials for 3D printing often exhibit inadequate damping properties, limiting their application in damping scenarios. However, 3D printing TPU filaments specifically engineered for enhanced damping performance frequently lack sufficient stiffness, causing printing continuity issues. To address these challenges, this study investigates the rational design of TPU composites by regulating TPU molecular structure and incorporating polylactic acid (PLA) to enhance both damping performance and stiffness. The results reveal that a prepolymer curing coefficient of 2.0, combined with a chain extender ratio of Dimethyl thio-toluene diamine (DMTDA) to 1,4-Butanediol (BDO) at 5:5, optimizes the damping and mechanical properties of the TPU material. Furthermore, by incorporating 30 wt% PLA particles into the TPU matrix, the obtained TPU7/PLA3 composite filament has excellent printability and admirable damping properties with a peak damping value of 0.60 around room temperature and an effective damping temperature range exceeding 100 °C. A lattice structure resembling Kelvin foam was successfully fabricated using the TPU/PLA filaments, demonstrating superior damping performance compared to commercial TPU filaments and underscoring its potential for energy absorption applications.