Photosensitized Cationic Polymerization of Cyclohexene Oxide Using a Phenacylanilinium Salt

The photoinitiated cationic polymerization of cyclohexene oxide with N-phenacyl-N,N-dimethylanilinium hexafluoroantimonate (PDA+SbF6–) and a polynuclear aromatic compound, such as perylene, anthracene or phenothiazine, or an aromatic carbonyl compound, such as benzophenone or thioxanthone, was studied at λinc > 340 nm. All the aromatic sensitizers except benzophenone and thioxanthone are effective in initiating the polymerization at wavelengths where PDA+SbF6– is transparent. An initiation mechanism is proposed that involves electron transfer from the excited sensitizer to PDA+SbF6–.