Shape Memory and Radiopaque Properties of PLA / PCL ‐Based Composites Containing Fe 3 O 4 Nanoparticles

ABSTRACT Biodegradable shape‐memory polymers have been proposed for stent application; however, their low radiopacity limits visualization under X‐ray imaging. To address this limitation, shape‐memory nanocomposites based on PLA/PCL blend incorporating iron oxide (Fe 3 O 4 ) nanoparticles were prepared. This study focused on determining the Fe 3 O 4 content required to impart radiopacity while minimizing deterioration of the original properties of the PLA/PCL blend. PLA/PCL composites containing Fe 3 O 4 nanoparticles were fabricated via extrusion and injection molding processes, and their rheological and mechanical properties were analyzed according to the Fe 3 O 4 content. Morphological and thermal analyses confirmed a two‐phase structure consisting of PLA as the fixed phase and PCL as the switching phase. Radiopacity was observed in the Fe 3 O 4 ‐containing samples. The 0.5 wt% Fe 3 O 4 nanocomposite exhibited the highest viscosity, suggesting relatively good nanoparticle dispersion and enhanced viscoelastic response. At higher Fe 3 O 4 contents, viscosity and crystallinity decreased, likely due to nanoparticle aggregation, changes in the internal structure, and restricted crystal growth. These results demonstrate that Fe 3 O 4 content significantly affects the rheological and structural properties of the nanocomposites.