Benzoin type photoinitiator for free radical polymerization |
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| Authors: | Duygu Sevinc Esen Nergis Arsu José P. Da Silva Steffen Jockusch Nicholas J. Turro |
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| Affiliation: | 1. Department of Chemistry, Yildiz Technical University, 34220 Davutpasa, Istanbul, Turkey;2. Centro de Investiga??o em Química do Algarve, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Campus de Gambelas, 8005‐139 Faro, Portugal;3. Department of Chemistry, Columbia University, New York, New York 10027 |
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| Abstract: | Benzoin, a popular photoinitiator for free radical polymerization of vinyl monomers, was improved by introduction of two methyl thioether substituents. This new benzoin derivative showed an about 50 times higher light absorption in the near‐UV spectral region and performed better than the unsubstituted benzoin in polymerization experiments in bulk solutions or films of acrylate monomers when low initiator concentrations are used. Laser flash photolysis, low temperature luminescence experiments and photoproduct studies by mass spectrometry suggest that a slow α‐cleavage mechanism (kα = 2.2 × 105 s?1) from the electronic triplet state with a quantum yield of 0.1 is the primary photoreaction to generate the initiating free radicals. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 |
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| Keywords: | laser flash photolysis photoinitiator photopolymerization photochemistry photophysics radical polymerization |
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