Graff Bernadette, Klee Joachim E, Fik Christoph, Maier Maximilian, Fouassier Jean Pierre, Lalevée Jacques
Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15, rue Jean Starcky, 68057, Mulhouse Cedex, France.
DENTSPLY DeTrey, De-Trey-Straße 1, Konstanz, Germany.
Macromol Rapid Commun. 2017 Jul;38(13). doi: 10.1002/marc.201600470. Epub 2016 Sep 16.
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.
一种基于双硅基酮（BSK）结构的新型光引发剂被提出，它是一种新型化合物，在暴露于蓝色发光二极管和绿色激光二极管时，能高效引发甲基丙烯酸酯（如双酚A - 甲基丙烯酸缩水甘油酯/三乙二醇二甲基丙烯酸酯共混物（70%/30% w/w））的聚合反应。通过实时傅里叶变换红外（FTIR）光谱记录聚合过程。利用吸收、荧光、电子自旋共振（ESR）和稳态实验来研究其中涉及的化学机理。还进行了分子轨道计算。值得注意的是，BSK在碘鎓盐存在下能有效发挥作用。引发步骤的整体机理得以阐明。这类新型的硅基自由基产生型光引发剂在甲基丙烯酸酯的光聚合反应中，例如在牙科材料中，确实具有很大的应用前景。
