Home > Blog  > Synthesis of magnesium stearate

Synthesis of magnesium stearate

2013-08-29 by seoer8

1 Preparation of sodium stearate 4.25 parts of sodium hydroxide dissolved in 50 parts of water, heated to 85 ℃ use. 25 parts of stearic acid into the reaction vessel, 500 parts of hot water, stirred and dissolved, adjust the temperature of 85 ~ 90 ℃. Have prepared the sodium hydroxide solution was slowly added with stirring to the acid solution, maintaining the temperature 75 ~ 80 ℃, to the end of the reaction with stirring. Liquid sodium stearate spare insulation product.
(2) Preparation of magnesium stearate , 15 parts of magnesium sulfate dissolved in 150 parts of water, heated to 55 ℃, and slowly added to the prepared solution of sodium stearate, in the metathesis reaction with stirring, the reaction of the hard magnesium stearate as a solid precipitate. After completion of the reaction, standing separation of serum, and then washed with water, centrifuge at 80 ~ 85 ℃ drying, ie finished.
3 the acid with 164mL of 46.6g 1mol / L sodium hydroxide solution, to obtain 50g of sodium stearate 2L water. The prepared solution of sodium stearate heated to 80 ℃, a mixture consisting of 20g of magnesium chloride dissolved in 100mL water to prepare a solution, stirring constantly, and soon white precipitate. After cooling, filtered, washed with water until no chloride ions are present, and finally washed with ethanol. 10g of product in concentrated sulfuric acid, placed in a vacuum desiccator for 4 weeks to obtain a product A [Mg (C18H35O2) 2.2 H2O]. The remaining product was dissolved in benzene and heated at reflux 20min, the upper layer of hot yellow liquid decanted and evaporated to dryness, the resulting solid can be recrystallized from benzene to give the product which B [Mg (C18H35O2) 2]. Product A in an oven at 105 ℃ for 2h after drying into anhydrous product B.

keywords:    pvc-additive