properties of stearic acid

The strain driven, solid vegetable fat obtained fatty acids, mainly composed of stearic acid (C18H36O2) and palmitic acid (C16H32O2).
 [Properties] white or creamy white with a sense of lumps or crystalline powder, its profile has microstrip shiny needle-like crystals; have similar micro-fat smelly, tasteless. This product is soluble in chloroform or ether, dissolved in ethanol, practically insoluble in water. This product's freezing point freezing point (appendix Ⅵ D) not less than 54 ℃. Iodine value iodine value of this product (Appendix Ⅶ H) is not greater than 4. Acid value acid value of this product (Appendix Ⅶ H) 203 - 210. Easy and magnesium stearate and calcium ions of calcium stearate and stearic acid reaction of magnesium (white precipitate).
 [Storage and validity] sealed.
 [Category] excipients.
 [Check] water-soluble acid to take this product 5g, heating and melting, add new content such as boiling hot water and shake for 2 minutes, let cool, filtered, the filtrate add 1 drop of methyl orange indicator solution, no significant red. Neutral fat or wax to take this product 1.0g, 0.5g anhydrous sodium carbonate and water plus 30ml, boil to dissolve, the solution should be clarified. Residue on ignition to take this product 4.0g, according to the law examination (Appendix Ⅷ N), 0.1% had left no residue. Residue on ignition Heavy metals take the residue left under the law examination (Appendix Ⅷ H second law), not containing heavy metals than parts per million.