Novel preparation and characterization of <scp>PA12</scp>/<scp>DMAc</scp> microspheres for selective laser sintering

Abstract A novel approach to investigate the processability of polyamide 12/dimethylacetamide (PA12/DMAc) microspheres for laser sintering through molecular interactions of the functional groups and the effects of DMAc on the morphology, particle size distribution, and thermal properties of the polymer composites was addressed in this study. The increase in DMAc concentrations enhanced polymer dissolution, minimized agglomeration, and improved the binding adhesive forces within the polymer matrix. It also enhanced the stretching vibrations in the primary amide (C=N), amine bond (C–N), and hydrogen bond (N–H) of the PA12. The melting enthalpy of the polymer powder increased with greater molecular interactions with the solvent. All the PA12 powder samples exhibited a consistent average crystallization point of 147.5°C, similar to that of virgin PA12 (149.3°C) due to identical exothermic properties. The SEM and particle size distribution analysis of PA12/DMAc samples indicated variability in molecular interspaces between powder particles due to differences in the interfacial mobility, which expanded with an increase in the solvent input ratios. However, the particle size distribution span reduced with an increase in the volume of DMAc. The optimal mean particle size distribution was 64.87 μm, accompanied by a bulk density of 0.38 g/cm 3 , which could facilitate the sinterability of the PA12 powder. Highlights Compatibility of PA12/DMAc microspheres Molecular interactions during TIPS Effects of DMAc on PA12 dissolution and precipitation time Dissolution and precipitation rate analysis Melting and crystallization behavior.