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Dilatometric investigations of fatty acid methyl esters
Author(s) -
Craig B. M.
Publication year - 1955
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02639682
Subject(s) - melting point , stearate , volume (thermodynamics) , chemistry , thermodynamics , materials science , analytical chemistry (journal) , organic chemistry , physics
Summary The coefficients of expansion and melting dilations were measured for methyl palmitate, methyl stearate, methyl arachidate, methyl behenate, and methyl oleate. The dilatometric curve for the heating cycle of methyl palmitate and methyl stearate in the solid state was composed of a linear section to 49 degrees below the melting point, followed by a curvilinear section to the melting point. The heating and cooling cycle curves for methyl palmitate show the same volume change from −38°C. to 29°C., but the shape of the curves is different. The same relation holds for methyl stearate from −38°C. to 37.5°C. “After‐contractions” were found in volume measurements within a few degrees of the melting point of both esters. Equilibrated points were found within 0.5 degrees of the final melting temperature of methyl stearate. A striking similarity exists between curves for variation of the dielectric constant with temperature for long chain linear molecules and the dilatometric data.