硅橡胶合成催化剂氢氧化四甲铵的制备新工艺

采用有效面积为4.5dm~2的全氟阳离子交换膜,在阳极室容积为500mL、阴极室容积为580mL的二室单膜电渗析槽内,以四甲基氯化铵为原料,制备了合成有机硅橡胶及其他有机硅产品聚合用催化剂氢氧化四甲铵(Me_4NOH)。阳极室四甲基氯化铵浓度为30％(质量),阴极室可得到纯度为 13％-15％、Cl~-<0.01％、Na~+<0.0001％和 K~+<0.000 5％的 Me_4NOH。产品经减压浓缩即得到 Me_4NOH·5H_2O晶体。

A NEW PROCESS FOR THE PREPARATION OF TETRAMETHYLAMMONIUM HYDROXIDE CATALYST USED IN THE POLYMERIZATION OF SILICONE RUBBERS

Tetramethylammonium hydroxide ( Me4NOH ) which was used as catalyst in the polymerization of organo silicone rubbers and other organo silicone products was synthesized from tetramethylammonium chloride by electrodialysis reaction in an electrodialysis cell which was separated into anodic and cathodic compartmens by a single layer of all fluro anionic exchange membrane having an effective area of 4.5 dm2. The anodic and the cathodic compartment had a volume of 500 mL and 580 mL, respectively. The aqueous solution of tetramethylammonium chloride, 30% in concentration ( mass), was introduced into the anodic compartment, and Me4NOH was obtained from the cathodic compartment at the concentration of 13%-15%, which contains impurities, i.e., Cl-<0.01%, Na+< 0.000 1%, and K+< 0.000 5%. The final product, the highly purified solid pentahydrate of Me4NOH, was obtained by evaporation of the crude product under reduced pressure.