Modeling of uniform polymerization via combined mechanism of photoinitiation and photothermal initiation

Abstract

The kinetics of near infrared (NIR) laser photothermal initiated and ultraviolet (UV) laser photoinitiated polymerization in thick polymer systems was theoretically presented. A uniform initiator concentration profile as time evolves can be obtained by combining two mechanisms, i.e., the photoinitiation and photothermal initiation. The photoinitiation rate was found to be a function of the temperature distribution, polymer thickness, laser intensity, illumination time, initiator absorptivity, and concentration. The temperature distribution due to the NIR laser heating process calculated via a one-dimensional heat equation. Meanwhile, the time evolution profile of the photoinitiation rate due to the combined mechanism calculated numerically. The numerical results provide useful guidance for the prediction of UV laser photoinitiated and NIR laser photothermally initiated polymerization particularly in thick polymer systems.