New Method for the Synthesis of Ammonium Salts of O,O′-Dialkyldithiophosphoric Acids on the Basis of Elemental Phosphorus and Sulfur—A Method for the Preparation of Effective Inhibitors for Carbon Dioxide Corrosion of Mild Steel

Abstract

New ammonium salts of O,O′-dialkyldithiophosphoric acids have been obtained based by the reaction of white phosphorus (P₄)–alcohol–amine–elemental sulfur. The reaction is characterized by full conversion of white phosphorus and is not accompanied by the release of hydrogen sulfide. It has been established that all studied compounds are highly efficient inhibitors of CO₂-mediated corrosion of mild steel active at concentrations of 0.25–5 mg·L⁻¹.

Keywords:

• Alcohols
• amines
• ammonium salts of O,O-dialkyldithiophosphoric acids
• carbon dioxide corrosion
• elemental sulfur
• inhibitors
• white phosphorus (Р₄)

Acknowledgments

Financial support from the Russian Foundation for the Basic Researches (No. 08-03-12004, No. 09-03-00006а) is gratefully acknowledged.