Multi-dimensional fillers synergistically enhanced thermal conductivity of TPU composites in selective laser sintering technology

With the rapid development of the electronic field, the requirements for thermal management materials are increasing to satisfy the heat dissipation of electronic devices. Due to the shortcomings of low precision and difficulty in forming thermal conductive composites with complex structures in traditional technologies, it is necessary to explore a new forming process. Selective laser sintering (SLS) is an important 3D printing technology, which can manufacture diverse parts with complex shapes and be used in various fields. In this study, TPU/AlN/h-BN/MWCNTs composites were successfully developed by selecting three different dimensions of thermally conductive fillers and combining them with the SLS process. The research shows that the thermal conductivity of TPU composites can reach up to 1.13 W/mK with 20 wt% AlN, 15 wt% h-BN, and 1 wt% MWCNTs hybrid fillers, which is 491 % higher than that of pure TPU, ascribed to the synergistic effect of multi-dimensional fillers. In addition, the tensile strength and elongation at break of TPU/AlN/h-BN/MWCNTs composites maintain 16.5 MPa and 294 %, which still has excellent mechanical properties. This work also investigated the influence of fillers on the SLS process, thermal stability, melting, and crystallization behavior of composites. It reveals an effective, feasible strategy for TPU composites with excellent thermal conductive and complex shapes. [Display omitted] •This study proposes a feasible and effective method to prepare composite materials with complex structures and excellent thermal conductivity.•TPU/AlN/ h-BN /MWCNTs composites were successfully prepared by the SLS process.•The effect of multi-dimensional fillers on enhancing thermal conductivity has been discussed and the hybrid filler composed of 20 wt% AlN, 15 wt% h-BN, and 1 wt% MWCNTs exhibited the best ability in enhancing the thermal conductivity of polymer matrix.