S-phenyl thiobenzoate as a new sulphur-containing photoinitiator: a product, laser flash photolysis and photopolymerization study
✍ Scribed by Hideo Tomioka; Yasuyuki Takimoto; Masaki Kawabata; Masahiko Harada; Jean-Pierre Fouassier; Denis Ruhlmann
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 886 KB
- Volume
- 53
- Category
- Article
- ISSN
- 1010-6030
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✦ Synopsis
Photolysis of the title compound (1) in benzene gives benzaldehyde, diphenylsulphide and biphenyl; these are formed from cu fission of the excited triplet state of 1 which yields benzoyl and thiyl radicals. The aryl substituent has a significant influence on the efficiency of photocleavage. The benzoyl radical is detected by time-resolved laser spectroscopy and the results of kinetic analysis are in complete agreement with those obtained from the product investigation. Photopolymerization of phenyldiethyleneglycol acrylate in the presence of 1 results in the formation of a polymer whose yield is roughly correlated with the photoreactivity of 1. The effect of initiator concentration on the photopolymerization efficiency suggests that 1 acts as an iniferter (initiator-transfer agent-terminator), with the benzoyl radical as initiator and the thiyl radical as terminator.