Two-step Preparation of Trazodone and Its Corrosion Inhibition Mechanism for Carbon Steel

Trazodone(TZD) was prepared via a two.step method taking 3-chloroaniline, 2,2'-[(3-chloropro. pyl) azanediyl] diethanol and 1,2,4-triazolo[4,3-a] pyridin-3(2H).one as raw materials. The corrosion inhibi. tion effect of TZD for 20# mild steel in 0.5 mol/L hydrochloric acid solution was evaluated through mass loss method, potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition mechanism was also revealed by virtue of scanning electron microscopy (SEM), atomic force microscopy (ATM), attenuated total reflection infrared spectroscopy and adsorption activation parameters. The results indicated that the corrosion inhibition efficiency increased with increase of TZD concentration and decreased with increase of temperature, which could reach 95.8% at a dosage of 6 mmol/L under 298 K. TZD could spontaneously adsorb on the steel surface with the exothermic property, which obeyed Langmuir adsorption isotherm. The adsorption of TZD on the steel surface could depress the cathodic and anodic reactions accompanied with an enhancement of interfacial polarization resistance. TZD was inclined to parallelly adsorb on the steel surface based on theoretical calculations.