Reaction kinetics in films. The hydrolysis of long-chain esters

Abstract The hydrolysis of the simple esters of the short-chain fatty acids in the bulk phase has been investigated under a variety of conditions (Moelwyn- Hughes 1933, pp. 87, 245). This has now been extended to the insoluble esters of the long-chain acids and alcohols. These are also of interest biologically, since the natural breakdown and resynthesis of fats are probably interfacial reactions. The work of Hughes and Rideal (1933) on the oxidation of the unsaturated fatty acids, and of Fosbinder and Rideal (1933) on the alkaline hydrolysis of γ-stearolactone, has shown that these interfacial or two-dimensional reactions may differ from those in homogeneous solution; chiefly in the possibility of controlling the true steric factor. In the present work also it has been found that the velocity of reaction between long-chain esters and alkali can be markedly altered by suitable changes in the molecular orientation. Such effects have been discussed in a previous communication (Alexander and Schulman 1937).