Enhancing blue-light-initiated photopolymerization in a three-component system: kinetic and modeling of conversion strategies

The kinetics for a 3-component (initiators) photopolymerization system is presented for both numerical solutions and analytic formulas. The dynamic profiles are simulated for oxygen, free radical, and conversion for various concentrations of the co-initiator. The measured system reported by Kirschner et al. showed that conversion could be improved by higher concentration of the additive initiators and the kinetic rate constants. These features are consistent with our modeling. Competing mechanisms between the reduction of conversion due to light intensity reduced (in thick polymer) and the reduction of oxygen inhibition (higher conversion) are analyzed in thick polymer. The optimal conditions are governed by the product function of the light intensity and main initiator concentration (C-0), in which conversion efficacy has a normal-trend proportional to C0I0, for the transient-state, but a reversed-trend for the steady-state. These new predicted findings are also explored numerically. Strategies for improved conversion include: increasing the photoinitiator concentration, the light dose and intensity, addition of oxygen scavengers and use of multiple photoinitiators. Oxygen inhibition could be pre-minimized by a pre-irradiation of a visible light, such that the following conversion by another visible or UV light is improved.

Automated summary

This study investigated the kinetics of a 3-component photopolymerization system, identifying strategies for improved conversion such as increasing photoinitiator concentration, light dose and intensity. It was found that oxygen inhibition could be minimized by pre-irradiation with visible light, leading to enhanced conversion by subsequent visible or UV light exposure.