Influence of Fused Deposition Molding Printing Process on the Toughness and Miscibility of Polylactic Acid/Polycaprolactone Blends

Toughness is a prerequisite for bone scaffold matrix material if such material is to be used in clinic. Blending with polycaprolactone (PCL) is the most used method to improve the toughness of polylactic acid (PLA), while improving their miscibility in the absence of the compatibilizer is always a challenge. To address this issue, the printing process was proposed to improve the miscibility of PLA and PCL. PLA/PCL Blends at different compositions were extruded into filaments and used to print samples. The results of Fourier transform infrared and thermogravimetric analysis indicate that the processing temperatures of the extruder and FDM printer do not cause the degradation of PCL in blend. Following, the influence of FDM printing process on their miscibility was investigated in terms of mechanical properties, surface morphology and melting behavior. Results show that the printing process can effectively improve the miscibility and toughness, and the most appropriate PCL concentration used to blend with PLA is 20 wt.%. At 20 wt.% PCL concentration, the printed blend has an elongation of 189%, which is an increase of about 950% compared with pure PLA. This research not only expands the PLA/PCL blend research, but also provides a process guidance for FDM printing PLA/PCL bone scaffolds.