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Monohydroxylation of unsaturated oils: II. Autoxidation‐reduction
Author(s) -
Venkateswara Rao G.,
Achaya K. T.
Publication year - 1970
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/bf02609496
Subject(s) - autoxidation , chemistry , induction period , iodine value , chloride , peroxide value , conjugated diene , peroxide , organic chemistry , nuclear chemistry , monomer , catalysis , polymer
After an initial induction period the rate of autoxidation of safflower oil was linear at 0–5 C under ultraviolet illumination in glass and proceeded to a maximum peroxide value of 2200. Reduction of hydroperoxy to hydroxy groups was easily accomplished by shaking with stannous chloride solution. The product showed hydroxyl value (HV) 76, iodine value (IV) (total) 122 and conjugated diene 20%. Attempts to increase the degree of this hydroxylation either by controlled oxidation, or by additional autoxidation after blocking the hydroxyl in the oncehydroxylated oil, or by autoxidizing in the presence of silver nitrate or stannous chloride, were unsuccessful. After preliminary treatment with an acidic earth, the rate of autoxidation of a commercial linseed oil was linear up to a PV of 1840. Reduction with stannous chloride gave a product with a HV of 50 containing 15% diene and 3% triene conjugation.