Thermally assisted 3D printing of bio-polymer with high solute loading with improved mechanical properties

In this study, a stereolithography process with thermal assistance is presented to address the tradeoff between the flowability and the high concentration of solute loadings at room temperature, by which the improved performance of polymers prepared by stereolithography 3D printing can be achieved. As a demonstration, an easily available polymer of polyethylene glycol diacrylate (PEGDA) with the solute loading of Polyethylene glycol (PEG) was designed for the potential biomedical applications. The maximum soluble concentration of PEG in PEGDA is less than 10 wt% at room temperature while the concentration reaches to 30 % with the temperature of 70 ℃. The comparative experiments proved that the concentration of high molecular weight PEG had a positive effect on the mechanical property of the PEGDA resin. The hardness of the sample printed by the PEGDA resin with PEG by the concentration of 30 wt% is three times higher than that of the PEGDA resin without solute. As the concentration of PEG increases from 15 wt% to 30 wt%, the Young’s modulus has been enhanced from 67.9 MPa to 131.4 MPa while the Young’s modulus for the PEGDA resin without solute is 39.6 MPa. The compression tests with 3D printed lattice structure illustrated that the compressive modulus of the PGEDA resin has been improved by nearly 600 % with the 30 wt% of PEG. The cell proliferation experiments showed that the PEGDA resin with the loading of PEG led to the higher cell activity comparing to the PEGDA resin without solute. The results indicate that the thermally assisted 3D printed PEGDA resin with the high loading of PEG has excellent mechanical properties for the potential biomedical application. This study is expected to demonstrate the thermally assisted stereolithography 3D printing process for the polymer with high solute loading, which contributes to explore the printable materials with improved performance.