- Method for preparing hexamethyl cyclotrisiloxane
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The invention discloses a method for preparing hexamethyl cyclotrisiloxane. The method comprises the following steps: (1) firstly, putting dimethyl dichlorosilane, an organic solvent and presto cyclotetroilazane into a reaction kettle, introducing an ammonia gas at minus 20 DEG C to 20 DEG C, and controlling the temperature to minus 30 DEG C to 30 DEG C to implement a reaction, so as to obtain a reaction liquid with hexamethyl cyclotrisiloxane, presto cyclotetroilazane and ammonium chloride; (2) putting alkali water into the reaction kettle, leaving to stand to separate a liquid, and collecting an upper-layer reaction liquid with hexamethyl cyclotrisiloxane and presto cyclotetroilazane; (3) performing vacuum distillation on the upper-layer reaction liquid obtained through liquid separationin the step (2), thereby obtaining the hexamethyl cyclotrisiloxane. The method has the advantages of being good in reaction selectivity, small in amount of byproducts and high in yield, and the moleyield of the hexamethyl cyclotrisiloxane is not less than 82%.
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Paragraph 0017-0032
(2018/03/24)
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