title: Development of Novel Photoinitiators as Substitutes of Camphorquinone for the LED Induced Polymerization of Methacrylates: A Bis-Silyl Ketone.
abstract: A new photoinitiator based on a bis-silylketone (BSK) structure is proposed as a novel compound leading to highly efficient initiating silyl radicals for the polymerization of methacrylates (e.g., a bisphenol A-glycidyl methacrylate/triethyleneglycol dimethacrylate blend (70%/30% w/w)) upon exposure to a blue light emitting diode and a green laser diode. The polymerization profiles are recorded by real time Fourier transform IR (FTIR) spectroscopy. Absorption, fluorescence, electron spin resonance (ESR), and steady state experiments are used to investigate the involved chemical mechanisms. Molecular orbital calculations are also carried out. Remarkably, BSK efficiently works in the presence of an iodonium salt. The overall mechanism for the initiation step is clarified. This novel class of silyl radical generating photoinitiators is really promising for the photopolymerization of methacrylates, e.g., in dental materials.
authors.affiliation: Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15, rue Jean Starcky, 68057, Mulhouse Cedex, France.
authors.forename: Bernadette
authors.initials: B
authors.lastname: Graff
authors.affiliation: DENTSPLY DeTrey, De-Trey-Straße 1, Konstanz, Germany.
authors.forename: Joachim E
authors.initials: JE
authors.lastname: Klee
authors.affiliation: DENTSPLY DeTrey, De-Trey-Straße 1, Konstanz, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Fik
authors.affiliation: DENTSPLY DeTrey, De-Trey-Straße 1, Konstanz, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Maier
authors.affiliation: Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15, rue Jean Starcky, 68057, Mulhouse Cedex, France.
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Fouassier
authors.affiliation: Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15, rue Jean Starcky, 68057, Mulhouse Cedex, France.
authors.forename: Jacques
authors.initials: J
authors.lastname: Lalevée
mesh_terms: D002164:Camphor / Q000031:analogs & derivatives / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000138:chemical synthesis*; D010777:Photochemistry; D058105:Polymerization
chemical_list: D003764:Dental Materials; D007659:Ketones; D008689:Methacrylates; D002164:Camphor; C553149:camphorquinone
keywords: bis-silylketone; camphorquinone; dental composites; photoinitiator; silyl radicals