Development of polyacid corrosion inhibitor with 2-vinylpyridine residue

A novel type of polyacid corrosion inhibitor (PCI) was synthesized from the residue of 2-vinylpyridine, which could reduce the cost of hazardous waste disposal in production enterprises, and solve the environmental pollution caused by residue. Herein, the components of the residue were analyzed and a special solvent is selected to dissolve it. Then, synergistic experiments of the residual solution with different inhibitor were carried out to select the corrosion inhibitor components, and the optimal ratio of each component was determined by orthogonal experiments. The performance of PCI was estimated by weight loss method, and its electrochemical type was detected by electrochemical experiments. It indicated that the main components of 2-vinylpyridine residue are pyridine derivatives and hydrocarbons. The developed PCI is composed by four components, which could be suitable for HCl, citric acid, sulfamic acid, other acid systems, and has good corrosion inhibition effect on carbon steel, brass, and other materials. The corrosion rate of N80 carbon steel can reach to 0.5491 g m−2 h−1 at 60 ℃ in 5% HCl, which fully meets the requirements of China national standards. The electrochemical polarization curve showed that PCI is a kind of highly effective mixed inhibitor, which can inhibit both cathode and anode simultaneously.