The Radical-Chain Oxidation of Tetrahydrofuran Inhibited by Tocopherol and Ascorbic Acid

The effect of ascorbic acid and α-tocopherol on the radical chain oxidation of tetrahydrofuran was studied at a temperature of 309 K. The reaction was initiated by 2,2'-azo-bis-isobutyronitrile. The process rate was monitored by the oxygen absorption. The rate constant of the tetrahydrofuran peroxyl radical reaction with α-tocopherol were measured k₇ = (2.9 ± 0.6) × 10⁵ l mol^–1 s^–1. The effect of an aqueous solution ascorbic acid on the oxidation rate of tetrahydrofuran was studied. The rate constant of the tetrahydrofuran peroxyl radical reaction with ascorbic acid were measured k₇ = (10.2 ± 1.0) × 10⁴ l mol^–1 s^–1. The effect of ascorbic acid on the tetrahydrofuran oxidation inhibited by α-tocopherol is considered. It has been shown that when both inhibitors are used together, the induction period is equal to the sum of the induction periods of individual compounds. The effective inhibition rate constant in this case is equal to k₇ = (2.5 ± 0.5) × 10⁵ l mol^–1 s^–1.