<> "The repository administrator has not yet configured an RDF license."^^ . <> . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan"^^ . "Oxymethylene dimethyl ethers (CH3O(CH2O)nCH3) bearing 3 to 5 CH2O-units (OMDME 3-5) are promising diesel additives, as they are able to reduce soot and NOx emissions. However, due to economic restrictions, an industrial synthesis process for these compounds has not been realized yet. As presented in this thesis, it was possible to synthesize oligomeric OMDME from dimethoxymethane (DMM) and trioxane (TRI), catalyzed by solid acids, in a more efficient and economical way as described in the literature.\r\nFor the first time, it was possible to carry out the synthesis of OMDME at atmospheric pressure and mild reaction temperatures below 40 °C, maintaining high reactivity. Besides optimizing process parameters and testing of catalysts, reaction kinetics were also evaluated and determined. Furthermore, the synthesis of oxymethylene diethyl ethers (OMDEE) and oxymethylene diacetate (OMDAc) was investigated and compared with each other.\r\nThe oligomerization of OMDME is a typical equilibrium reaction. In addition to DMM and TRI as starting materials, a series of oligomeric OMDME are also present in the equilibrium. All tests showed that the OMDME product mixture follows the Schulz-Flory distribution, even with varying DMM/TRI ratios. Solid acids, such as cation exchanger resins and zeolites, served as catalysts. Out of all tested resins and zeolites, Amberlyst36 among resins and BEA25 among zeolites exhibited the strongest catalytic activity. The chemical equilibrium was reached within a few minutes at room temperature. However, this high reactivity was only possible, when the synthesis of OMDME was performed in the absence of water, as minor traces of water already caused a significant loss of catalyst activity. \r\nFor the first time, it was further possible to verify that during the oligomerization the direct insertion of TRI into DMM takes place. This was observed due to an increased OMDME 4 concentration at the beginning of the reaction. Because of these and other results, a detailed reaction mechanism was postulated, which implies the insertion of TRI into the catalytically activated DMM. The proven high rate of transacetalization in the OMDME reaction led to the Schulz-Flory distribution even before chemical equilibrium was reached.\r\n"^^ . "2015" . . . . . . . "Ludger Peter"^^ . "Lautenschütz"^^ . "Ludger Peter Lautenschütz"^^ . . . . . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan (PDF)"^^ . . . "Ludger Lautenschütz - Heidelberg 240715.pdf"^^ . . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan (Other)"^^ . . . . . . "indexcodes.txt"^^ . . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan (Other)"^^ . . . . . . "lightbox.jpg"^^ . . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan (Other)"^^ . . . . . . "preview.jpg"^^ . . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan (Other)"^^ . . . . . . "medium.jpg"^^ . . . "Neue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan (Other)"^^ . . . . . . "small.jpg"^^ . . "HTML Summary of #19210 \n\nNeue Erkenntnisse in der Syntheseoptimierung oligomerer Oxymethylendimethylether aus Dimethoxymethan und Trioxan\n\n" . "text/html" . . . "540 Chemie"@de . "540 Chemistry and allied sciences"@en . .