Continuous Optical 3D Printing of Green Aliphatic Polyurethanes.

We report the first-time continuous optical 3D printing using green aliphatic polyurethanes (gPUs). Photo-sensitive diurethane monomers are prepared from six-membered cyclic carbonate functionalized with methacrylate and biogenic amines. The synthesized monomers are then polymerized to isocyanate-free gPU by UV crosslinking using a continuous optical printing (COP) method. 3D structures with user-defined mechanical properties and biologically relevant structures are printed in mere seconds with a high throughput and resolution by COP. The physical properties of gPU structures are characterized on the transparency, stiffness, and thermal behavior. Finally, the biocompatibility of the gPUs was studied by seeding cells on top of the structures. The technology developed in this work can be used to tailor-make novel gPU materials with specific properties and fabrication process from various functional cyclic carbonates and polyamines. Such printable isocyanate-free gPU materials could fulfill the demands to critical safety issues required in biomedical and consumer products applications. 3D-printed gPU devices could have broader applications such as mechanically strong and durable medical implants, tissue engineering scaffolds, micro-fluidic devices, diagnostic probes, and lab-on-a-chip systems.