Stiff 3D-Printable TPU/CNF composite materials for damping and vibration reduction

Owing to its tunable molecular structure and processability, thermoplastic polyurethane (TPU) is extensively applied as an ideal damping material and employed in 3D printing. However, conventional damping TPUs lack sufficient stiffness for the fused deposition modeling (FDM) process, and commercially available 3D printable TPU filaments typically exhibit poor damping performance, which limits the applicability and scalability of damping TPU materials. To resolve the intrinsic antagonism, this study engineered three distinct types of carbon nanofibers (CNFs) to modify TPU damping materials, developing a series of TPU/CNF composites suitable for FDM. The results indicated that platelet carbon nanofiber (P-CNF) provided a superior modification effect on TPU compared with tubular and herringbone counterparts. With the 1 wt % P-CNF content and 3.0-curing coefficient TPU, the prepared TPU/CNF composite exhibited a broad damping temperature range exceeding 80 °C and an elastic modulus of 18.08 MPa, demonstrating excellent damping performance and 3D printability. Compared to commercial filaments, the samples printed using TPU/P-CNF damping composite exhibit superior vibration reduction effects, highlighting the material's application potential in the field of damping and vibration reduction. This work established a nano-reinforcement strategy for next-generation 3D printing of high-performance damping materials toward customization, functionality, and scalability.