Kinetics of the radical-chain oxidation of methyl oleate inhibited by 5-amino-6-methyluracil and 5-amino-1,3,6-trimethyluracil

The effects of 5-amino-6-methyluracil (AMU) and 5-amino-1,3,6-trimethyluracil (ATMU) on the rate of oxygen uptake in methyl oleate (MO) radical-chain oxidation initiated by 2,2′-azobisisobutyronitrile as a model reaction have been investigated. The rate constant (k7) for the reactions of the peroxyl radical forming from MO with AMU and ATMU at 333 K in the medium of the substrate being oxidized has been measured. k7 is (1.7 ± 0.2) × 104 L mol−1 s−1 in the presence of AMU and (1.3 ± 0.2) × 104 L mol−1 s−1 in the presence of ATMU. k7 for MO oxidation in aqueous cetyltrimethylammonium bromide solution takes a much smaller value of (2.8 ± 0.8) × 103 L mol−1 s−1.