Biodegradable photocurable PCL/PEG-diacrylate for 3D printing

Polycaprolactone (PCL) is one of the biodegradable synthetic polymers. For 3D printing applications, PCL parts were mostly printed by melt-and-dispense-type or sintering-type approaches, but few were using photopolymerization due to photocurable PCL is not commercially available. In our previous works, photocurable PCL, PCL-diacrylate (PCL-DA), was synthesized in house, dissolved in acetone, and mixed with polyethylene glycol diacrylate (PEG-DA). The efficiency of PCL-DA synthesis was unknown, and the existence of evaporable acetone may introduce dimension instabilty. Therefore, in this research, the conversion rate of PCL-DA was studied by adjusting synthesis parameters, and acetone was removed from the material system. The properties of cured materials were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and water absorption rate measurement. As a result, better PCL-DA conversion rate was achieved, exposure time and formability of different ratio of PCL-DA/PEG-DA (6:4, 5:5, 4:6, 3:7, and 2:8) were compared, and thermal properties and water absorption ratio of cured materials were revealed.