Propriétés et utilisation de l’huile de ricin

Castor and its derived oil, the so-called ‘‘castor oil’’, are known from the ancient times, when the oil was used for cosmectics, or as a laxative, or as a fuel in lamps. Nowadays, castor oil has a completely renewed interest, not for its direct applications, but thanks to various possibilities in downstream processing, which involves chemical modifications & reactions. Indeed, castor oil has this specifiticy of a remarkable uniformity, with about 90% of the fatty acid chains of the triglyceride composed of ricinoleic acid, a natural fatty acid behaving a hydroxyle group, which is a unique feature in vegetal oils. Then, it is possible to envision reactions either on the ester group, on the double bond or even on the hydroxyle moety to yield a variety of chemicals. In this paper, after a short description of the castor plant, we give statistics on the production of castor grains and an overview on the oil extraction process. Then, we report the market prices before listing the main properties of castor oil. These latter are quite specific and explain the large variety of possible direct applications. At last, the possible chemical transformations are listed, before giving two practical cases, as actual industrialisation success stories.