Abstract
Hydrogen donation from butylated hydroxyanisole (BHA) and/or butylated hydroxytoluene (BHT) to the peroxyl radical prepared by cobalt-catalyzed cleavage of tert-butylhydroperoxide was investigated, and the relation of this process to synergism in the antioxidative effect was discussed. BHA initially donated a hydrogen to the peroxyl radical to form its phenoxyl radical, and this radical reacted with either the peroxyl radical or another phenoxyl radical to form o-benzoquinone or the dimer. BHT reacted with the peroxyl radical to form its adduct. In the combination of BHA and BHT, BHA donated a hydrogen to the peroxyl radical initially, and its phenoxyl radical accepted hydrogen from BHT to regenerate BHA, with enhanced oxidation of BHT to quinone methide. This hydrogen acceptance of the phenoxyl radical of BHA from BHT may be closely correlated with the synergism in the antioxidative effect of the mixture of BHA and BHT.
