Corrosion Inhibition Properties of Propylenediamine-Type Double Mannich Base Acidizing Corrosion Inhibitor

The 1,2-propanediamine and 1,3-propanediamine were reacted with paraformaldehyde and acetophenone, respectively, two corrosion inhibitors 1,2-propanediamine type double Mannich base (BTM-2) and 1,3-propanediamine type double Mannich base (BTM-3) were prepared. The influence of the addition amount of corrosion inhibitor on the corrosion inhibition effect of N80 steel in 15% HCl solution was analyzed by atmospheric pressure static coupon weight loss test and electrochemical test. And the quantum chemical calculation method was used to futher discuss the corrosion inhibition mechanism. The results showed that both BTM-2 and BTM-3 had obvious corrosion inhibition effect, and the corrosion inhibition effect of BTM-2 was better than that of BTM-3. BTM-2 and BTM-3 corrosion inhibitor molecules all produced combined adsorption of physical adsorption and chemical adsorption on the surface of N80 steel, forming a layer of adsorption film, its adsorption conformed to the Langmuir adsorption isotherm model. The quantum chemical calculation result was consistent with experimental result.