Mathematical modelling for 1,6-hexanediol diacrylate photopolymerization in presence of oxygen

A dynamic model is proposed for the photopolymerization of 1,6-hexanediol diacrylate (HDDA) with the bifunctional initiator bis-acylphosphine oxide (BAPO) in the presence of oxygen. The model tracks time-varying concentrations of monomer, oxygen, and different radical end groups using ordinary differential equations. An analytical expression is derived for the mass-transfer of oxygen. Oxygen-related parameters are estimated using real-time Fourier-transform infrared reflection (FTIR) vinyl conversion data, which were collected during polymerization of HDDA films with different thicknesses, initiator concentrations, and light intensities. The resulting model and parameter estimates provide good predictions for experiments involving thin films up to 12 μm, with BAPO levels ranging from 1 to 4 wt.% and relatively low light intensities (200–1000 W/m2).