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Determination of the total unsaturation of tung oil by catalytic hydrogenation
Author(s) -
Pack F. C.,
Planck R. W.,
Dollear F. G.
Publication year - 1952
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/bf02645650
Subject(s) - degree of unsaturation , iodine value , catalysis , acetic acid , stearate , chemistry , organic chemistry
Summary The use of catalytic hydrogenation as a quantitative method for the measurement of total unsaturation in tung oil and related products containing conjugated unsaturation, has been investigated. The apparatus, which comprises essentially a gas burette, manometer, and reaction vessel, is relatively simple, is constructed entirely of glass, and employs an externally mounted magnetic agitator. The weighed sample and platinum catalyst are suspended in glacial acetic acid during hydrogenation. In the case of tung oil and partially hydrogenated tung oil, heating of the reaction vessel is necessary to complete the hydrogenation. Hydrogen iodine values representing the total unsaturation in domestic and imported oils, alpha‐ and beta‐eleostearic acids, the residual unsaturation in partially hydrogenated tung oils, and the unsaturation of other organic materials are reported. Tung oil and eleostearic acid gave hydrogen iodine values of approximately 240 and 271, respectively. Analytical hydrogenation, as described, is particularly well suited for the determination of unsaturation in conjugated systems.