Synthesize And Study Of A Novel Vapor Phase Inhibitor

A novel heterocyclic amine organic-salt vapor phase inhibitor, named YC-1 was designed and synthesized based on the relationship between the structure and effect of inhibitor. Its corrosion inhibition effect and mechanism for carbon steel and brass under marine atmosphere were studied by weight-loss measurement, weak polarization curves, Tafel curves and electrochemical impedance spectrum.The result of weight-loss experiments showed that the different active units in YC-1 molecule had strong intramolecular synergic effect, as a result, its corrosion inhibition efficiency was much higher than its two units used separately. The results of weight-loss experiments, electrochemical impedance spectrum and weak polarization curves all showed that YC-1 had a good corrosion inhibition effect for brass under marine atmosphere and also had somewhat protection for carbon steel.The results obtained from Tafel curves showed that YC-1 was an anodic inhibitor for carbon steel. After adding YC-1, corrosion potential moved nobly, the slope of anodic polarization curve increased and anodic process was inhibited. As for the brass, at the presence of YC-1, the corrosion potential shifted positively, both of the slopes of anodic and cathodic polarization curves increased and their processes were inhibited significantly. This indicated that YC-1 was a mixed inhibitor for brassThe corrosion mechanism of carbon steel and brass in different medium systems was investigated by using variance analysis of the results of parameters calculated by Mansfeld, Leloy, Baraartt. The results indicated that cathodic process of carbon steel under marine atmosphere was controlled by concentration polarization and active polarization, while the corrosion process of brass was controlled by the process of cathodic oxygen diffusion.The results based on electrochemical impedance spectrum showed that the real part at low frequency of carbon steel contracted after adding YC-1, the diameter of EIS increased. As for the brass, the EIS is capacity arc at high frequency and line at low frequency. With addition of yc-1, the diameter of capacitive arc at high frequency increased significantly.The influence of temperature on VPIs' corrosion inhibition efficiency under marine atmospheres was also investigated in this article. The result showed that the corrosion velocities of the blank carbon steel and brass increased with the raising of the temperature at first, then with the further increase of temperature, their corrosion velocities both begin to decrease and reach their lowest value at 80 and 70 respectively. The influences of temperature on the corrosion rate became more complex after adding inhibitor. There are three types of v-t curves-parabola,logarithm and exponential.