A novel UV-curable acryl-polyurethane for flexural 3D printing architectures

An acryl-functionalized urethane prepolymer series with various compositions were synthesized using polyethylene glycol (PEG) and hexamethylene diisocyanate (HDI). A novel acryl-urethane resin (AU) was designed by the addition of 2-hydroxyethyl methacrylate (2-HEMA) as a suitable material for digital light processing (DLP) 3D printing. The optimizing photo-initiator and additive were selected by UV-spectroscopy. The formulation containing the UV-curable AU resin and photo-curable additives was exposed to 405 nm UV radiation to produce the flexible 3D architectures. The effects of the photo-initiator/multifunctional acrylate value and UV absorptive power on the 3D printing performance were evaluated in terms of the mechanical properties and dimensional resolution. When the acryl-urethane resin/base acrylate ratio was 1/9, the UV-cured APU formulations had the excellent mechanical properties and highest resolution. The surface properties of the 3D architectures were tuned by controlling the photo-initiator type and composition in the AU resin. Overall, this novel UV-curable AU resin can be a promising prepolymer for the DLP printing of flexible photo-resin for biocompatible and photo-curable applications.