Hydrolytically Degradable Poly(β-amino ester) Resins with Tunable Degradation for 3D Printing by Projection Micro-Stereolithography

Applications of 3D printing that range from temporary medical devices to environmentally responsible manufacturing will benefit from printable resins that yield polymers with controllable architecture, material properties, and degradation behavior. Towards this goal, poly(beta-amino ester) (PBAE)-diacrylate resins are investigated due to the wide range of available chemistries and tunable material properties. PBAE-diacrylate resins are synthesized from hydrophilic and hydrophobic chemistries and with varying electron densities on the ester bond to provide control over degradation. Hydrophilic PBAE-diacrylates led to degradation behaviors characteristic of bulk degradation, while hydrophobic PBAE-diacrylates led to degradation behaviors dominated initially by surface degradation and then transitioned to bulk degradation. Depending on the chemistry, the crosslinked PBAE-polymers exhibited a range of degradation times under accelerated conditions, from complete mass loss in 90 min to minimal mass loss at 45 days. Patterned features with 55 mu m resolution are achieved across all resins, but their fidelity is dependent on PBAE-diacrylate molecular weight, reactivity, and printing parameters. In summary, simple chemical modifications in the PBAE-diacrylate resins coupled with projection microstereolithography enable high-resolution 3D printed parts with similar architectures and initial properties but widely different degradation rates and behaviors.

Automated summary

PBAE-diacrylate resins offer a wide range of available chemistries and tunable material properties for 3D printing applications. Depending on the chemistry, these resins can exhibit varying degradation behaviors, from bulk degradation to surface degradation, with different degradation rates under accelerated conditions. The high-resolution 3D printed parts achieved through simple chemical modifications in the resins combined with projection microstereolithography have similar architectures and initial properties but diverse degradation behaviors.