Surprising radical mechanisms of antioxidant polysulfides

An image showing a liquid stream of a motorcycle motor oil

Source: © Shutterstock

Tetrasulfide prevents oxidation of petroleum products through radical reactions 

Researchers in Canada have discovered that the antioxidant properties of polysulfides are due to their radical reactivity rather than ionic mechanisms, contrary to previous wisdom. They found that tetrasulfides are better radical-trapping antioxidants for petroleum products than the most common industrial antioxidant additives.