- Shape selectivity extending to ordered supermicroporous aluminosilicates
-
In the synthesis of polyoxymethylene dimethyl ethers (PODEn) catalyzed by ordered supermicroporous aluminosilicates, shape selectivity was observed and the high selectivity for target products (PODE3-8) was attributed to the particul
- Fu, Wen Hua,Liang, Xiao Min,Zhang, Haidong,Wang, Yi Meng,He, Ming Yuan
-
-
Read Online
- Synthesis of polyoxymethylene dimethyl ethers from methylal and trioxane catalyzed by Br?nsted acid ionic liquids with different alkyl groups
-
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
-
-
Read Online
- Synthesis of polyoxymethylene dimethyl ethers catalyzed by rare earth compounds
-
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
-
-
Read Online
- AQUEOUS COMPOSITION BASED ON POLYOXYMETHYLENE DIALKYL ETHERS (POM) AND THEIR USE FOR THE PRESERVATION AND/OR EMBALMING OF THE HUMAN OR ANIMAL BODY
-
The invention relates to a composition comprising: a) a mixture of polyoxymethylene dialkyl ethers (POM) having a restricted specific molecular distributionb) at least one biocidal agentc) at least one pro-penetrating agentd) at least one dyee) optionally, another additiveand water as diluent. It also relates to a non-therapeutic method of preserving and/or embalming a dead human or animal body using the composition, such as the use of this composition for anatomopathological purposes.
- -
-
Paragraph 0060-0061
(2020/11/24)
-
- Towards a Sustainable Synthesis of Oxymethylene Dimethyl Ether by Homogeneous Catalysis and Uptake of Molecular Formaldehyde
-
Oxymethylene dimethyl ethers (OMEn; CH3(-OCH2-)nO-CH3, n=3–5) are a novel class of sustainable synthetic fuels, which are of increasing interest due to their soot-free combustion. Herein a novel anhyd
- Peter, Andreas,Fehr, Samuel M.,Dybbert, Valentin,Himmel, Daniel,Lindner, Ines,Jacob, Eberhard,Ouda, Mohamed,Schaadt, Achim,White, Robin J.,Scherer, Harald,Krossing, Ingo
-
supporting information
p. 9461 - 9464
(2018/07/25)
-
- By poly-formaldehyde systems poly formaldehyde method of dimethyl ether
-
The invention relates to a method for preparing polyoxymethylene dimethyl ether from paraformaldehyde, and mainly solves the problem in the prior art that the cost is relative high when triformol is adopted as a raw material to synthesize polyoxymethylene dimethyl ether. According to the invention, methanol, dimethoxymethane, and paraformaldehyde are adopted as raw materials, wherein the mass ratio of methanol : dimethoxymethane : paraformaldehyde is (0-10) : (0-10) : 1, wherein the quantities of methanol and dimethoxymethane cannot both be 0; the catalyst is chosen from at least one component of the following tombarthite modified solid superacid: SO4/ZrO2-La2O3, SO4/ZrO2-Ce2O3, Cl/TiO2-La2O3, Cl/TiO2-Ce2O3, Cl/Fe2O3-Ce2O3, SO4/Al2O3-La2O3 or S2O8/ZrO2-La2O3. The technical scheme excellently solves the problem, and can be applied to the industrial production of polyoxymethylene dimethyl ether.
- -
-
Paragraph 0019-0020
(2017/02/09)
-
- Polyoxymethylene to dimethyl ether synthesis method of polyoxymethylene
-
The invention relates to a method for synthesizing polyoxymethylene dimethyl ether by using polyoxymethylene, and the method is mainly used for solving the problems of low reaction efficiency of the traditional catalyst and relatively high cost caused by taking trioxymethylene as a raw material. The problems are better solved according to the technical scheme that methanol, dimethoxymethane and polyoxymethylene are used as raw materials, wherein the mass ratio of methanol to dimethoxymethane to polyoxymethylene is (0-10):(0-10):1, the dosages of methanol and dimethoxymethane cannot be simultaneously equal to zero, the raw materials are in contact with a catalyst to react to generate polyoxymethylene dimethyl ether under the conditions that the reaction temperature is 70-200 DEG C and the reaction pressure is 0.2-6MPa, the dosage of the catalyst accounts for 0.05-10% of the weight of the raw materials, and the adopted catalyst comprises the following components in parts by weight: 30-80 parts of molecular sieve carriers (a) and 20-70 parts of rare earth modified solid super acid (b). The method can be used for industrial production of polyoxymethylene dimethyl ether.
- -
-
Paragraph 0019; 0020; 0035; 0036
(2017/03/21)
-
- REACTION SYSTEM AND PROCESS FOR PREPARING POLYMETHOXY DIMETHYL ETHER
-
The invention relates to a reaction system and process for continuously preparing polymethoxy dimethyl ether (DMM3-8) by a continuous acetalization reaction between an aqueous formaldehyde solution or paraformaldehyde and methanol in the presen
- -
-
Paragraph 0105-0108
(2015/04/15)
-
- Reaction system and process for preparing polymethoxy dimethyl ether
-
The invention relates to a reaction system and process for continuously preparing polymethoxy dimethyl ether (DMM3-8) by a continuous acetalization reaction between an aqueous formaldehyde solution or paraformaldehyde and methanol in the presence of a functionalized acidic ionic liquid as a catalyst. The reaction system of the invention preferably comprises a formaldehyde-concentrating unit, a vacuum-drying unit, an acetalization reaction unit, a product-separating unit and a catalyst-regenerating unit. The process of the invention uses aqueous formaldehyde solution as an initial raw material, which is concentrated in the formaldehyde-concentrating unit to a concentrated formaldehyde of 50～80 wt.%, and vacuum-dried to paraformaldehyde, or uses paraformaldehyde as raw material directly, then obtains DMM3-8 by an acetalization reaction. The raw materials of the reaction used in the invention are cheap and available easily, and the utilization rate of formaldehyde is high; an efficient separation between the catalyst and product, as well as the reuse of the catalyst and raw materials, are realized by a separation mode of combining extraction and rectification together.
- -
-
Paragraph 0073; 0074
(2015/04/15)
-
- A method for synthesizing polyoxymethylene dimethyl ethers
-
The present invention relates to the field of chemical engineering and technology, in particular relates to the sub-field of synthesis of high quality alternative liquid engine fuel from non-petroleum based feedstock, more particularly relates to a method
- -
-
Paragraph 0043-0044
(2015/01/16)
-
- PERFLOURINATED POLY(OXYMETHYLENE) COMPOUNDS
-
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.
- -
-
Page/Page column 20-21
(2010/07/10)
-
- METHOD FOR PRODUCING POLYOXYMETHYLENE DIMETHYL ETHERS
-
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
- -
-
Page/Page column 6
(2008/06/13)
-
