| Abstract Scope |
Laser-based powder bed fusion (L-PBF) of thermoplastics requires high processing temperatures (173–250 °C), which can lead to thermal aging and reduced part performance. Incorporation of thermosetting polymers offers a low-temperature alternative via in-situ crosslinking but is limited by rapid gelation and poor process control. This study experimentally investigates thermoplastic polyurethane (TPU)-modified epoxy powders for L-PBF using a selective laser polymerization (SLP) approach. TPU/epoxy blends (25/75, 50/50, 75/25 wt%) were characterized using SEM, DSC, and FTIR to assess morphology, thermal behavior, and processability. Single-layer SLP experiments combined with in-situ infrared thermography revealed improved powder flowability, melt stability, and layer uniformity with TPU addition. The 50/50 composition showed optimal performance, achieving effective melt coalescence and controlled epoxy curing at 0.304 J/mm˛. Results highlight the role of thermal gradients and process control in forming stable interpenetrating networks, demonstrating the potential of reactive L-PBF for advanced thermoset additive manufacturing. |