Radical scavenging abilities of hydrogen-donating hydrocarbons from petroleum

The reaction rates of hydrogen-donating hydrocarbons from petroleum (HHAPs) with 2,2-diphenyl-1-picrylhydrazyl (DPPH) were studied in comparison with the conventional hindered phenolic antioxidants and the typical hydroaromatics, and the following results were obtained: (1) The conventional hindered phenolic antioxidants have much higher reaction rates than tetralin and octahydrophenanthrene. (2) Some of HHAPs exhibited reaction rates as high as or higher than the conventional hindered phenolic antioxidants. (3) These high reaction rates are attributable to the heavier fractions of HHAPs. These high radical scavenging abilities elucidate the many and diverse inhibiting effects against the degradation of various hydrocarbon products, already reported.