Bio-based polyamide 1012 powder with strengthened hydrogen bonding interactions for sustainable laser additive manufacturing

Bio-based polyamide powders, such as polyamide 1012 (PA1012), are promising materials for sustainable laser additive manufacturing (AM) technologies. However, they generally exhibit poor processability and high moisture sensitivity. Herein, we demonstrate that the AM behavior and water resistance of PA1012 could be enhanced by regulating intermolecular hydrogen bonding interactions. Stronger hydrogen bonds formed in PA1012 powders upon incorporating a thermoplastic phenolic resin (PF), leading to broader processing windows and lower melt viscosities, allowing the fabrication of parts with fewer defects and superior mechanical performance. Incorporating 5–15 wt% PF reduced the water absorption of PA1012 parts by 54–57 %, thereby largely improving their mechanical and dimensional stabilities in humid conditions. Moreover, PF suppressed the post-condensation and deterioration of unfused powders. Therefore, strengthening the hydrogen bonding interactions in polyamide powder offers a simple strategy to enhance the part performance in humid conditions and promote the sustainability of laser additive manufacturing.