Title of article :
The vaporization enthalpies and vapor pressures of fatty acid methyl esters C18, C21 to C23, and C25 to C29 by correlation – gas chromatography
Author/Authors :
James S. Chickos، نويسنده , , Hui Zhao، نويسنده , , Gary Nichols، نويسنده ,
Issue Information :
دوهفته نامه با شماره پیاپی سال 2004
Abstract :
Vapor pressures and vaporization enthalpies for methyl heptadecanoate and methyl heneicosanoate to methyl octacosanoate exclusive of methyl tricosanoate are evaluated as a function of temperature over the temperature range T = 298.15–450 K by correlation gas chromatography. The results are generated by an extrapolative process using literature values for methyl tetradecanoate to methyl eicosanoate as standards. Relationships for calculating vapor pressures of the title compounds from T = 298.15 to 450 K are provided. Experimental fusion enthalpies are also reported for the methyl esters from methyl hexadecanoate to methyl octacosanoate excluding methyl tridecanoate. Vaporization enthalpies and fusion enthalpies adjusted for temperature to T = 298.15 K are combined to provide sublimation enthalpies. The results are compared to available literature values. A rationale for the linear relationship observed between enthalpies of vaporization and enthalpies of transfer from solution to the vapor is also provided.
Keywords :
Phase change , Sublimation , Fatty acid methyl esters , Enthalpy , Vapor pressures , Vaporization
Journal title :
Thermochimica Acta
Journal title :
Thermochimica Acta