- Synthesis of polyoxymethylene dimethyl ethers from methylal and trioxane catalyzed by Br?nsted acid ionic liquids with different alkyl groups
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Br?nsted acid ionic liquids with different alkyl group carbon chain lengths and an alkane sulfonic acid group were synthesized through bromoalkane, imidazole and 1,4-butane sultone as raw materials. The structures and properties of the ionic liquids were experimentally characterized. Catalytic reaction of methylal (DMM) with trioxane (TOX) for preparation of polyoxymethylene dimethyl ethers (PODMEn, CH3O(CH2O)nCH3, where n > 1) was investigated in various Br?nsted acid ionic liquids with different carbon chain length of alkyl groups. The carbon chain length of alkyl groups and activity correlation for the ionic liquids was studied. It was found that the structures of ionic liquids were consistent with the designed structure and their purities were high. They possessed high thermal stability and wide liquid range. The hydrophobicity of ionic liquids became stronger with the increase of carbon chain length. With increasing the carbon chain length of ionic liquids, the selectivity of PODME3-8 is increased at first and then decreased. Among all the ionic liquids, [C6ImBS][HSO4] shows the best catalytic performance and the selectivity of PODME3-8 is 57.85%.
- Wu, Qin,Li, Weijiao,Wang, Min,Hao, Yu,Chu, Tonghua,Shang, Jiqing,Li, Hansheng,Zhao, Yun,Jiao, Qingze
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p. 57968 - 57974
(2015/07/20)
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- Synthesis of polyoxymethylene dimethyl ethers catalyzed by rare earth compounds
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Polyoxymethylene dimethyl ethers (PODMEn) have been synthesized in moderate yields by the reaction of methylal (PODME1) and paraformaldehyde catalyzed by rare earth compounds. The activities of catalyst in the reaction were investigated and the
- Shi, Gao-Feng,Miao, Jian,Wang, Guo-Ying,Su, Jin-Mei,Liu, Hai-Xiao
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p. 2149 - 2153
(2015/11/28)
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- PERFLOURINATED POLY(OXYMETHYLENE) COMPOUNDS
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Compounds of Formula (I): R1-O-(CF2-O)n-R1, wherein: n is an integer from 2 to 100; and R1 is perfluorinated alkyl or substituted perfluorinated alkyl are described. Also described are methods of preparing the compounds of Formula (I). For example, compounds of Formula (I) can be prepared by providing a poly(oxymethylene) compound and fluohnating the poly(oxymethylene) compound, for instance, via direct aerosol fluorination.
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Page/Page column 20-21
(2010/07/10)
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- METHOD FOR PRODUCING POLYOXYMETHYLENE DIMETHYL ETHERS
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The invention relates to a method for producing a polyoxymethylene dimethyl ether of formula H3CO(CH2O)nCH3, in which n = 2 - 10. According to said method, methylal and trioxane are fed to a reactor and are reac
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Page/Page column 6
(2008/06/13)
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