Research on the Mechanism of Accelerator for Photocurable Resin in 3D Printing

The photopolymerization kinetics of cycloaliphatic epoxide and oxetane wi th accelerators were investigated with Real-time Fourier transform infrared spectroscopy（RT-FTIR）.The consumption rates of epoxy group and oxetane group as a function of time were obtained by monitoring of the absorption peaks in the 789 cm-1 and 981 cm-1.The effect of accelerators type and the accelerating mechanism were discussed.In general,benzyl alcohol and its analogues with electron-donating substituents are useful accelerators for the cationic polymerization of cycloaliphatic epoxide and oxetane.Activated monomer mechanism and free-radical chain-induced decomposition of onium salt cationic photoinitiator account for the observed accelerating effect on the polymerization rate.