Tetraacylgermanes as highly efficient photoinitiators for visible light cured dimethacrylate resins and dental composites |
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Authors: | Norbert Moszner Urs Karl Fischer Iris Lamparth Pascal Fässler Judith Radebner Anna Eibel Michael Haas Georg Gescheidt Harald Stueger |
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Affiliation: | 1. Ivoclar Vivadent AG, Schaan FL‐9494, Liechtenstein;2. Institute of Inorganic Chemistry, Technische Universit?t Graz, Graz A‐8010, Syria;3. Institute of Physical and Theoretical Chemistry, Technische Universit?t Graz, Graz A‐8010, Syria |
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Abstract: | Tetrabenzoylgermane 1 and various substituted tetrabenzoylgermanes 2 – 7 were investigated as visible light (VL) photoinitiators (PIs) for dental dimethacrylate resins and dimethacrylate‐based composites. The tetrabenzoylgermanes 1 – 7 show a very strong VL absorption between 400 and 450 nm. Substituents on the benzoyl chromophore strongly influence their properties such as melting point, solubility, absorption behavior, or PI reactivity. A good photobleaching behavior and a very high reactivity as VL PI was found in photo‐differential scanning calorimeter experiments for selected tetrabenzoylgermanes. Composite pastes containing only ~0.1 wt % of Ge‐PI exhibited a sufficient photocuring due to the high PI‐reactivity of the tetraacylgermanes. Among the investigated germane PIs, tetrakis(2‐methylbenzoyl)germane 2 shows the best performance as VL PI for restorative composites and enables the composites to be photocured using an LED with an emission maximum of 500 nm. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46115. |
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Keywords: | composites photopolymerization radical polymerization resins |
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