Dehydrated castor oil (DCO) is manufactured by the chemical dehydration of castor oil, to give a product with a relatively high degree of conjugation. It can be used in many surface coating applications, particularly when short drying times are required.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.
