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Polymorphic behavior of erucic acid
Author(s) -
Suzuki M.,
Sato K.,
Yoshimoto N.,
Tanaka S.,
Kobayashi M.
Publication year - 1988
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/bf02546013
Subject(s) - differential scanning calorimetry , erucic acid , polymorphism (computer science) , oleic acid , solubility , crystallography , thermal stability , chemistry , calorimetry , materials science , thermodynamics , organic chemistry , fatty acid , biochemistry , physics , gene , genotype
Polymorphic behavior of erucic acid was examined by differential scanning calorimetry (DSC), X‐ray diffractometry (XRD) and optical microscopy. Four individual polymorphs were observed, α 1 , γ 1 , α and γ. The single crystals of α and α 1 were obtained from acetonitrile solutions. DSC and XRD studies exhibited reversible transformations between α and γ, and between α 1 and γ 1 . The two transformations were characterized by an order (γ and γ 1 )‐disorder (α and α 1 ) transformation due to melting of the aliphatic chain between a cis double bond and a methyl end group, as revealed in α and γ of oleic acid. The thermodynamic stability among the four polymorphs was determined based on the transformation features and the solubility data. α 1 is most stable above 25.9 C, melting at 34.0 C, α is most stable in a range of temperature between −1.0 and 25.9 C, transforming in a crystalline state to α 1 at 31.2 C on heating. γ is most stable below −1.0 C. It can be concluded that the polymorphism of erucic acid is different from that of oleic acid with respect to the thermal and structural behaviors, although some similarities are revealed.