RAPID MEASUREMENTS OF BOILING-POINT AND VAPOR-PRESSURE OF SHORT-CHAINTRIGLYCERIDES BY THERMOGRAVIMETRIC ANALYSIS

Temperature dependence of vapor pressure and the boiling points for tr icaproin (Tcap) and tricaprylin (Tcpy) were measured by a new rapid th ermogravimetric analysis (TCA) method. Results were in agreement with data from other references. The Clausius/Clapeyron model fitted Tcap a nd Tcpy vapor pressure data with errors of 6% or less for pressures ra ng ing from ambient down to 20 mmHg. This agreement with the model sug gests that the vapor of these compounds has a large degree of ideal ga s behavior and that their vaporization enthalpies are nearly constant from 25 to 400 degrees C. Comparable accuracy and precision were obtai ned with TCA and differential scanning calorimetry methods fbr the com pounds tested; however, TCA plots had significantly straighter baselin es, which made vapor pressure determinations more convenient.