Dehydrated castor oil (DCO) is manufactured by the chemical dehydration of castor oil, to give a product with a relatively high degree of conjugation. The triglycerides in castor oil contain a large percentage (83-90%) of ricinoleic fatty acid. This fatty acid contains a hydroxyl group so when it is dehydrated a new carbon-carbon double bond is created. This effectively turns a non-drying oil into a drying oil as the new double bond is conjugated to the double bond already present. DCO has good water resistance and durability properties and also non-yellowing properties which make it ideal for surface coating applications such as varnishes. Other applications of DCO include brake linings, alkyd resins, printing inks, mastics and sealants.
