Knobbe, Martens, Olson & Bear, LLP
Method for preparing polyoxymethylene dimethyl ethers by acetalation reaction of formaldehyde with methanol
It is disclosed a method for preparing polyoxymethylene dimethyl ethers by continuous polymerization and acetalation reactions. The method may include two steps: performing a polymerization reaction of an aqueous formaldehyde solution under catalysis of an ionic liquid IL I to obtain a mixed aqueous solution of trioxymethylene and formaldehyde; and an acetalation reaction of the mixed aqueous solution of trioxymethylene and formaldehyde with methanol is performed under catalysis of an ionic liquid IL II to prepare polyoxymethylene dimethyl ethers. The method may use an aqueous formaldehyde solution as a starting material to prepare polyoxymethylene dimethyl ethers by continuous polymerization and acetalation reactions, achieving a high use ratio of formaldehyde. A film evaporator is used in the invention, realizing a rapid separation and recycling of the light components, with a high separation efficiency. The separation of the catalyst is simple, thereby realizing recycling of the catalyst.
Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences
Y B B B C C Y
Y02P B01J B01J B01J C07C C07C Y02P
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Heyuan Jing Zhen Chungu
Song Chen Li Xia