Photopolymerization kinetics of α-disulfone cationic photoinitiator

An α-disulfone cationic photoinitiator called 4-tolyl methyl disulfone was synthesized and characterized by UV–vis absorption spectroscopy, LCMS, IR and NMR. Eight vinyl ether monomers were chosen to study the kinetics of photopolymerization by real-time infrared spectroscopy (FT-IR). It showed that 4-tolyl methyl disulfone was an effective cationic photoinitiator. The rate of polymerization and ultimate conversion increased with increase of 4-tolyl methyl disulfone concentration and light intensity.

► Under UV light, photolysis occurred for TMDS in methanol to form sub-sulfonic acids.
► TMDS has a maximal absorption of 237 nm in ethanol due to π–π* transition with ɛmax = 2.73 × 104 L mol−1 cm−1.
► Eight vinyl ether monomers were chosen to study the kinetics of photopolymerization by real-time infrared spectroscopy (FT-IR).
► TMDS was an effective cationic photoinitiator. Both rate of polymerization and final conversion was increased with increase in TMDS concentration and light intensity.