Hyperchlorinated fatty acids. II. Photochlorination of stearic acid in carbon tetrachloride, reaction study.

Abstract

AbstractThe free radical chlorination of stearic acid in carbon tetrachloride was studied with variation of the chlorine flow rate, the active light intensity and the initial fatty acid concentration. In addition the variation of temperature with time was measured. The chlorine flow rate affects only the reaction time and modifies neither the chlorine content of the products obtained nor the yield, approximating 100%. On the other hand, the initial fatty acid concentration seems to be the prime factor determining the chlorine content of the products. Similarly, the onset of the polymerization of the chlorinated monomers depends essentially on the initial fatty acid concentration. These polymers are probably chlorinated polyesters. This behavior can be explained by the incursion of radical ions RCOO·+ resulting from irradiation of exciplexes formed by interaction between the more or less highly chlorinated fatty acid and the solvent. These interactions take place when the fundamental complex occupies a critical volume, which depends on the acid concentration.