Synthesis and Formulation of PCL-Based Urethane Acrylates for DLP 3D Printers.

Hsuan Chen,Shyh-Yuan Lee,Yuan-Min Lin

doi:10.3390/polym12071500

Abstract

In this study, three PCL-based polyurethane acrylates were synthesized and further formulated into twelve resins for digital light processing (DLP) 3D printing. Three PCL diols with different molecular weights were synthesized via ring-opening reaction of ε-caprolactone on diethylene glycol, with the catalyst stannous octoate. Isophorone diisocyanate (IPDI) was reacted with 2-hydroxyethyl acrylate (2-HEA) and the PCL diols form PCL-based polyurethane acrylates. Twelve resins composed of different percentages of PCL-based polyurethane acrylates, poly (ethylene glycol) diacrylate (PEGDA), propylene glycol (PPG) and photo-initiator were further printed from a DLP 3D printer. The viscosities of twelve resins decreased by 10 times and became printable after adding 30% of PEGDA. The degree of conversion for the twelve resins can reach more than 80% after the post-curing process. By changing the amount of PEGDA and PPG, the mechanical properties of the twelve resins could be adjusted. PUA530-PEG-PPG (70:30:0), PUA800-PEG-PPG (70:30:0), and PUA1000-PEG-PPG (70:30:0) were successfully printed into customized tissue scaffolds. Twelve PCL-based polyurethane photo-curable resins with tunable mechanical properties, cytotoxicity, and degradability were successfully prepared. With the DLP 3D printing technique, a complex structure could be achieved. These resins have great potential for customized tissue engineering and other biomedical application.

Highlights

Polyurethanes (PU) have been widely applied in biomedical applications for decades
Many of the previous studies reported the thermoplastic polyurethane for fused deposition modeling (FDM) method rather than photo-curable polyurethanes for digital light processing (DLP) 3D printers
Three different PCL diols were synthesized via ring-opening polymerization of -caprolactone (ε-CL) in the presence of diethylene glycol (DEG) (Figure 1)

Summary

Introduction

Polyurethanes (PU) have been widely applied in biomedical applications for decades. Polycaprolactone (PCL) were chosen as the diol. PCL has been widely used in the biomedical field, due to its excellent biocompatibility [4,5]. With the development of 3D printing technologies, researchers have started to synthesize PCL-based polyurethanes with 3D printing in recent years [6]. Many of the previous studies reported the thermoplastic polyurethane for fused deposition modeling (FDM) method rather than photo-curable polyurethanes for DLP 3D printers

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Discussion

Conclusion