Dilatometric studies of pure triglycerides and mixtures

Abstract

Summary The melting dilations and the coefficients of expansion of the solid and liquid states have been reported for five symmetrical mixed triglycerides and three simple triglyceride . The melting dilations were found to decrease with increasing proportions of oleic acid in the triglyceride molecule. In some simple mixtures the melting dilations of the several phases were found to occur discretely, but in the more complex systems there was an extension and overlapping of the melting ranges. In the mixtures of triolein with more saturated triglycerides, the melting point of triolein was found to be generally unaffected, but the melting points of the more saturated glycerides were lowered by the presence of triolein. Calculations of the solid‐to‐liquid ratios from dilatometric data were found to be impossible in the more complex mixtures due to wide variations in the melting dilations of the several phases and to the overlapping of their melting ranges. Approximate calculations of solid‐to‐liquid ratios in simple systems in which melting dilations occur discretely can be accomplished if the melting dilations of the individual triglycerides are known.