Characterization of the three major polymorphic forms and liquid state of tristearin by Raman spectroscopy |
| |
Authors: | Eric Da Silva Dérick Rousseau |
| |
Institution: | a Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto, Ontario, Canada, M5B 2K3 b Laboratoire de Physique des Systèmes Complexes, Université Picardie Jules Verne, 33 rue St Leu 80039 Amiens Cedex, France |
| |
Abstract: | Raman spectroscopy was used to distinguish the differences in the molecular organization of the α, β′ and β polymorphs, as well as the liquid state, of tristearin with focus placed on the C O, C H and C C Raman-active stretching regions. The ester carbonyl stretching region permitted polymorphic discrimination due to significant differences in the number of modes, their relative frequencies and their full-widths at half-maximum. In the liquid state, the absence of obvious signatures in this region indicated that many local micro-environments likely exist about the ester carbonyl of molten tristearin. The ratio between the symmetrical and asymmetrical C H stretching modes was linearly correlated with the enthalpy of fusion for each polymorph. The C C stretching modes, which provided insight into the trans/gauche content, were polymorph independent, but changed significantly upon transition into the liquid state (p < 0.05). Overall, Raman spectroscopy allowed for the quick discrimination of tristearin polymorphs from a conformational and thermodynamic perspective. |
| |
Keywords: | Raman spectroscopy Triglyceride Liquid state Crystallization Polymorphism Enthalpy |
本文献已被 ScienceDirect 等数据库收录! |
|