Improving selective laser sintering property of PA1212 powder by polydopamine: Physical coating vs in-situ coating

Abstract

Polydopamine (PDA) is a kind of biomimetic material with promising anti-aging applications in additive manufacturing. In this study, PDA-coated polyamide 1212 (PA1212) powders were prepared by using the physical mixing method and in-situ coating method, respectively. The effect of PDA on the properties and laser sintering behavior of PA1212 powder was then evaluated. The results showed that PDA improved the thermal stability of PA1212 powder while maintaining a wide sintering window. Although the hot-stage experiments suggested that the coalescence behavior of powders was affected to some extent, the sintered parts exhibited only a few structural defects, better mechanical properties, and improved thermo-oxidative stability due to the high photothermal conversion efficiency and free radical scavenging ability of PDA. Sintering results suggested that the in-situ coating of PDA on the surface of PA1212 powder in the form of films could manufacture parts with better comprehensive properties than that of the physical mixing method.