3D printing preview for stereo-lithography based on photopolymerization kinetic models

The diversity of biomedical applications makes stereolithographic (SL) three-dimensional (3D) printing process complex. A strategy was developed to simulate the layer-by-layer fabrication of 3D printed products combining polymerization kinetic with reaction conditions to realize print preview. As a representative example, the typical UV-curable dental materials based on epoxy acrylate and photoinitiator with different molar ratios was exposed under varying intensity of UV light to verify the simulation results. A theoretical kinetics model containing oxygen inhibition was established. In-situ FTIR was employed to measure propagation and termination constants while coupled UV/vis was performed to examine the law of light attenuation during cure reaction, even with various colours and additives. Simulation results showed that the correlation coefficient square between the experiments and simulations of epoxy acrylate with 1%, 2% and 3% initiator upon 20 mW/cm(2) UV light are 0.8959, 0.9324 and 0.9337, respectively. Consequently, our simulation of photopolymerization for SL 3D printing successfully realized visualization of printing quality before practically printing the targeted biomedical objects with complex topology structures.