A review of zinc dialkyldithiophosphates (ZDDPS): characterisation and role in the lubricating oil

This is a review of the additive, zinc dialkyldithiophosphate (ZDDP), which is found commonly in lubricating oil where it plays a role as both an antioxidant and an antiwear additive. This zinc complex is highly effective but its mechanisms of action have not been definitively reported. This review covers work pertaining to the characterisation and mechanisms of action of ZDDP and includes studies carried out by sophisticated instrumentation as well as laboratory studies. There are some references to the nature of the antiwear films generated by ZDDP and the usefulness of its derivatives.