Optimization of Fabrication Process of Polylactide Microparticles Tailored for Surface‐Selective Laser Sintering

Abstract

Surface‐selective laser sintering (SSLS) allows fabrication of 3D structures with a well‐defined architecture via sintering of polymeric microparticles. In this work, polylactide microparticles stabilized with alkylated chitosan were prepared via an oil‐in‐water emulsion solvent evaporation method and used as starting material to produce 3D structures via SSLS. A Box–Behnken experimental design was employed to optimize three microparticle fabrication parameters– stirring speed (300–900 rpm), alkylated chitosan concentration (0.5–1.5 wt.%), and stirrer type (two‐, three‐, or four‐blade)—aiming to maximize the yield of the target fraction (0–200 μm). Only the alkylated chitosan concentration exhibited a statistically significant effect on the target fraction yield (p = 0.0023), while stirring speed and stirrer type showed a nonsignificant tendency but did not reach the significance level (p > 0.05). Under optimal conditions, the target fraction yield reached 32.58 ± 0.49 wt.%, representing a 1.8‐fold increase compared to the non‐optimized conditions (18 wt.%). The optimized microparticles exhibited a regular spherical shape, smooth nonporous surface morphology, and a narrow monomodal size distribution with a mean diameter of 63 ± 24 μm and a Span of 0.95. The particles possessed a bulk density of 213.7 ± 1.2 kg/m3, a theoretical specific surface area of 0.0904 ± 0.0451 m2/g, and a water adsorption capacity of 0.0375 ± 0.0037 g/m2. The prepared microparticles were successfully utilized in SSLS to fabricate 3D structures, confirming their suitability as raw material for this process.