| This study is based on the measurement and collection of thermodynamic and physical property data, including vaporization enthalpy, fusion enthalpy, sublimation enthalpy and vapor pressure. Our interests have been in developing new methods of measuring these properties, indirectly, to permit this evaluation in instances where these properties can't be evaluated directly.; The following projects are among the studies that have been completed: (1) The vaporization enthalpies of high energy density fuels RP-1, JP-7, JP-8 used for aerospace propulsion have been determined. Most fuels currently in use are complex mixtures of hydrocarbons. The physical properties of fuel mixtures are essential in the design of equipment to handle them and as a mean of monitoring quality control. The vaporization enthalpies are also important properties in developing endothermic fuels that can be used in advanced aircraft. We thus use gas-chromatography in a novel manner to measure the vaporization enthalpies of complex mixtures. The average HIC ratio in several fuels has been measured by 1H NMR, and their average molecular weight has also been determined using gas chromatography. In instances where comparison with literature values was possible, our results were in good agreement. (2) The vaporization enthalpies and vapor pressures of a series of fatty acid methyl esters, C18, C21 to C23, C25 to C29, have been determined. The saturated fatty acid methyl esters (FAMEs) are used indirectly in a wide range of food, pharmaceutical and cosmetic applications. They are also promising substitutes for chlorinated hydrocarbons in industrial process, green fuel substitutes for diesel fuel and lubricants. Very few studies are available for the larger homologues of FAMEs. This is a study of the vapor pressures and vaporization enthalpies of larger FAMEs using correlation gas chromatography. (3) The measurement of the sublimation enthalpy of dimethyl 1,4-cubanedicarboxylate and dimethyl 2,6-cuneanedicarboxylate was also completed. These measurements are important in evaluating the strain energy of cubane, a high energy booster used in rocket propulsion. Also determined in this work were the vaporization enthalpy, fusion enthalpy and structure of 3:4, 5:6-dibenzo-2-hydroxymethylenecyclohepta-3,5-dieneone and related compounds. |
