The cause of castor oil instability, specifically in the following aspects: ① Because polar castor oil, with a strong affinity for water, hygroscopic strong performance in the castor oil, castor oil can easily make when alkali refining emulsification phenomenon. A part of the soap is formed into a colloidal solution of the oil phase, resulting in difficult to separate.
The cause of castor oil instability ② proportion of castor oil and the water is very close, so after washing alkali refining could easily lead to a two-phase stratified difficulties, improper operation, easy to form emulsification.
The cause of castor oil instability ③ ricinoleic acid in castor oil under certain conditions prone to generate intramolecular dehydration octadecadienoic acid melting at a melting point of 56 ℃ octadecadienoic acid and 54 ℃ in Mangold acid. If the drying process castor improper intramolecular dehydration of these high melting point of the unsaturated dicarboxylic acid, refined oil will reduce the transparency, decreased product quality, non-drying oil and castor oil to the drying oil change.
The cause of castor oil instability ④ Due to the castor oil fatty acid in the first 12 carbon atoms, a hydroxyl group makes the role of the double bond carbon atoms 9 and 10-bit more active, easily oxidized to azelaic acid. Therefore, the dehydration of castor oil under high temperature, degree of vacuum and the deodorization temperature requirements are more stringent.