Alternative methods for dehydrating castor oil

Summary Castor oil can be effectively dehydrated by non‐conjugated oil‐maleic anhydride adducts to give use‐ful paint or yarnish oils. Castor acids dehydrated in the presence of alumina form diene acids of 60% two double bond conjugation. The glyceride from these acids dries more rapidly to a tack‐free film than conventional dehydrated castor oil. In both of these processes the course of dehydration is believed to be the decomposition of esters of the alcohol groups in ricinoleic acid. Acidic ion exchange resins exert some catalytic effect in the dehydration of castor oil, but the oil so made is inferior in color and film properties.