Photoinitiation Mechanism and Ability of Thioxanthone-Based Versatile Visible Photoinitiators

Abstract

The development of visible photoinitiating systems has been attracting increasing attention due to their great applications in various fields. Three thioxanthone (TX) derivatives differing by their substituent groups have been investigated as photoinitiators (PIs) for visible photopolymerization. They could be used one-component PIs to initiate free radical polymerization. And, a two-component system with an iodonium could initiate cationic polymerization and hybrid polymerization, and could make interpenetrating polymer networks (IPN) synthesis. The high efficiency of these systems was found as being worthwhile for photocomposites preparations. Moreover, the mechanism of these TX derivatives is clarified using computational quantum chemistry, fluorescence quenching, steady-state photolysis, cyclic voltammetry and electron spin resonance spin-trapping techniques.

Keywords: Thioxanthone derivatives, Photopolymerization, IPN