2,2-dimethoxy-2-phenylacetophenone DMPA

Bisphenol-A-glycidyldimethyacrylate (Bis-GMA) 1565-94-2 2,2-dimethoxy-2-phenylacetophenone (DMPA) 24650-42-8 Oil Red O (Solvent Red 27) 1320-06-5 Oil Blue N (Solvent Blue 14) 2646-15-3 Fluorescent Yellow 3G (Solvent Yellow 98) 12671-74-8 Ethanol 64-17-5... 

Materials. A high viscosity epoxy diacrylate resin and an acrylate diluent were used to prepare the UV-cured films. The photoinitiator was 2,2-dimethoxy-2-phenylacetophenone, DMPA. Stabilizers are identified in Table I. All materials were from commercial sources and used as received from the suppliers. 

For a comparison the interaction of the initiators 2,2-dimethoxy-2-phenylacetophenone (DMPA), (2-hydroxy-2-propyl)phenone la (bothnon-coreactive) and the epoxide If with silica was also investigated.Silica was treated with 0.5 weight equivalent of these compounds in the same manner as previously described for the silanes Id,e. Ihe resulting materials were analyzed by e.a. (Table III). The results of e.a. are primarily given as percent carbon because the structure of the organic species on silica is not absolutely clear (a trihydroxy compound is assumed as derivative of If). 

Methacrylic acid (MAA) (Fluka, >98% stabilized with 0.025% hydrochinon monomethylether), the photoinitiator 2,2-dimethoxy-2-phenylacetophenone (DMPA, Aldrich, 99%), poly(methacrylic acid) (poly(MAA), Polysciences, lot 547827, 5% water) and iso-butyric acid (IBA, Fluka, p.a., >99.5%) were used as supplied. Demineralized water was used for preparing the reaction solutions. 

Ionic conductivity of PSEG gel PSEG having pendent vinyl groups was mixed with tetrafunctional thiol, pentaerythritol tetrakis(2-mercaptopropionate) (4TP-5), and photoinitiator, 2,2-dimethoxy-2-phenylacetophenone (DMPA), in acetonitrile. Lithium perchlorate was dissolved to the mixture. The ratio for [Li] / [-0-] was in the range of 0.025 - 0.317. After the polymer was crosslinked by UV light (1.6 J/cm% the obtained sample was dried for 48 h at ambient temperature. 

A similar approach was followed by Meier and coworkers, which allowed variation of the isocyanide component [54]. In this case, stearic acid served as onset for the chain elongation via Passerini-3CR along with 10-undecenal and various isocyanides. 10-Undecenal, because of its terminal double bond, enabled the subsequent thiol-ene addition of 3-mercaptopropionic acid with 2,2-dimethoxy-2-phenylacetophenone (DMPA) as photoinitiator. The newly introduced carboxylic acid provided reactivity for further sequences of Passerini-3CRs and thiol-ene... 

BenzUketals are another important class of photoinitiators (Table 4) developed for free-radical vinyl polymerization. Benzilketals exhibit higher thermal stability than benzoin compounds due to the absence of thermally labile benzylic hydrogen. The most prominent member of this class is the commercially used 2,2-dimethoxy-2-phenylacetophenone (DMPA). This initiator shows an excellent efficiency in photopolymerizations and is, at the same time, easy to synthesize. Other benzilketals are also suitable initiators but do not reach the price performance ratio of DMPA. 

A long life time of the triplet state tends to lead to a reduced overall quantum yield, because chances are higher that alternative deactivation routes may successfully compete with radical formation. 2,2-Dimethoxy-2-phenylacetophenone (DMPA) is an example for an initiator with a rather short-lived first triplet state (t<0.1 ns)," causing a high quantum yield The quantum yield rm for the formation of macroradicals from the initiator fragment radicals is also known as the initiator efficiency, /, which is defined analogously to the efficiency of thermal initiators. 

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