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Development of Novel Photoinitiators as Substitutes of Camphorquinone for the LED Induced Polymerization of Methacrylates: A Bis‐Silyl Ketone
Author(s) -
Graff Bernadette,
Klee Joachim E.,
Fik Christoph,
Maier Maximilian,
Fouassier Jean Pierre,
Lalevée Jacques
Publication year - 2017
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201600470
Subject(s) - photoinitiator , photopolymer , polymerization , methacrylate , photochemistry , glycidyl methacrylate , polymer chemistry , materials science , fourier transform infrared spectroscopy , radical polymerization , silylation , chemistry , polymer , organic chemistry , chemical engineering , monomer , engineering , catalysis
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.