Effect of Oxygen Inhibition on the Kinetic Constants of the UV-Radical Photopolymerization of Diurethane Dimethacrylate/Photoinitiator Systems

Abstract

The kinetic constants of propagation (kp) and termination (kt) for a diurethane dimethacrylate/1-hydroxycyclohexyl phenyl ketone (Irgacure 184) system were measured using a dark polymerization technique that employs real-time FT-IR spectroscopy to measure the conversion and reaction rate of the methacrylate group at different time points. The sample was placed between two optically polished KBr plates with a 10 μm metal spacer. A series of measurements resulted in a gradual peak in the kinetic constants at a 0.15 conversion of the methacrylate group. The kinetic constants for the conversion, which ranged from 0.15 to 0.5, were used to obtain the parameters of the Anseth–Bowman model to generate a numerical simulation of the photopolymerization kinetics. The kinetic equations, the oxygen inhibition reaction-diffusion equation, and the macroradical mass balance model indicated that the gradual peak in the kinetic constant was caused by an oxygen inhibition reaction. The Anseth–Bowman model for kp and kt was...