The solid-liquid phase diagrams of binary mixtures of consecutive, even saturated fatty acids: differing by four carbon atoms.
The complete solid-liquid phase diagrams for four binary mixtures of saturated fatty acids are presented, for the first time, in this work. These mixtures are formed by caprylic acid (C(8:0))+lauric acid (C(12:0)), capric acid (C(10:0))+myristic acid (C(14:0)), lauric acid (C(12:0))+palmitic acid (C(16:0)) and myristic acid (C(14:0))+stearic acid (C(18:0)). The phase diagrams were obtained by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). FT-Raman spectrometry and polarized light microscopy were used to complement the characterization for a complete understanding of the phase diagram. All of the phase diagrams here reported show the same global behavior that is far more complex than previously accepted. They present not only peritectic and eutectic reactions, but also metatectic reactions, due to solid-solid phase transitions common in fatty acids, and regions of solid solution not previously reported. This work contributes to the elucidation of the phase behavior of these important biochemical molecules with implications in various industrial applications.
Costa
Mariana C
MC
LPT, Department of Chemical Process, School of Chemical Engineering, State University of Campinas, UNICAMP, P.O. Box 6066, 13083-970 Campinas, SP, Brazil. mccosta@feq.unicamp.br
Sardo
Mariana
M
Rolemberg
Marlus P
MP
Ribeiro-Claro
Paulo
P
Meirelles
Antonio J A
AJ
Coutinho
João A P
JA
Krähenbühl
M A
MA
D002244:Carbon / Q000032:analysis / Q000737:chemistry*; D045424:Complex Mixtures / Q000737:chemistry*; D005227:Fatty Acids / Q000737:chemistry*; D005583:Fourier Analysis; D008859:Microscopy, Polarization; D044367:Phase Transition; D013059:Spectrum Analysis, Raman; D013696:Temperature; D014961:X-Ray Diffraction
D045424:Complex Mixtures; D005227:Fatty Acids; D002244:Carbon