The average functionality (number of hydroxyl groups per triglyceride molecule) of castor oil is 2.7, so it is widely used as a rigid polyol and in coatings. One particular use is in a polyurethane concrete where a castor-oil emulsion is reacted with an isocyanate (usually polymeric methylene diphenyl diisocyanate) and a cement and construction aggregate. This is applied fairly thickly as a slurry, which is self-levelling. This base is usually further coated with other systems to build a resilient floor.Castor oil is not a drying oil, meaning that it has a low reactivity with air compared with oils such as linseed oil and tung oil. Dehydration of castor oil yields linoleic acids, which do have drying properties. In this process, the OH group on the ricinoleic acid along with a hydrogen from the next carbon atom are removed yielding a double bond which then has oxidative cross-linking properties yielding the drying oil. Precursor to industrial chemicals
Castor oil can react with other materials to produce other chemical compounds that have numerous applications. Transesterification followed by steam cracking gives undecylenic acid, a precursor to specialized polymer nylon 11, and heptanal, a component in fragrances. Breakdown of castor oil in strong base gives 2-octanol, both a fragrance component and a specialized solvent, and the dicarboxylic acid sebacic acid. Hydrogenation of castor oil saturates the alkenes, giving a waxy lubricant. Castor oil may be epoxidized by reacting the OH groups with epichlorohydrin to make the triglycidyl ether of castor oil which is useful in epoxy technology.
In the 1986 film Stand by Me, protagonist Gordie tells his friends a story in which castor oil is used to violently disrupt a pie-eating contest. See also
Castor wax
List of unproven and disproven cancer treatments

References
Further reading
Naughton, Frank, "Castor Oil", Kirk-Othmer Encyclopedia of Chemical Technology, New York: John Wiley, doi:10.1002/0471238961.0301192014012107.a01.pub2, ISBN 9780471238966 – overview of chemical properties and manufacturing of castor oil

External links

International Chemical Safety Card 1452