Polymerization of dehydrated castor acids using an acid earth catalyst

The atmospheric pressure polymerization of a commercial dehydrated castor oil fatty acid mixture, by using as catalyst the acid clay Filtrol 13, has been studied under different conditions of temperature, catalyst concentration, reaction time, and concentration of conjugated linoleic acid in the starting material. At 180C or above, extremely rapid polymerization of the conjugated fatty acids occurred (50% complete in about 4 min at 66% concentration). This was accompanied bytrans isomerization and some hydrogen transfer to form oleic (oriso-oleic) acids. The ratio of dimer/polymer in the product was approximately 2 to 2.5 and was only slightly affected by variation in the reaction conditions.