Structural Evolution of PCL during Melt Extrusion 3D Printing

Screw-assisted material extrusion technique is developed for tissue engineering applications to produce scaffolds with well-defined multiscale microstructural features and tailorable mechanical properties. In this study, in situ time-resolved synchrotron diffraction is employed to probe extrusion-based 3D printing of polycaprolactone (PCL) filaments. Time-resolved X-ray diffraction measurements reveals the progress of overall crystalline structural evolution of PCL during 3D printing. Particularly, in situ experimental observations provide strong evidence for the development of strong directionality of PCL crystals during the extrusion driven process. Results also show the evidence for the realization of anisotropic structural features through the melt extrusion-based 3D printing, which is a key development toward mimicking the anisotropic properties and hierarchical structures of biological materials in nature, such as human tissues.