ELECTROCHEMICAL STUDIES OF POLYASPARTIC ACID ANDSODIUM TUNGSTATE AS CORROSION INHIBITORS FORBRASS IN 3 NaCl SOLUTION

摘要

Polyaspartic acid (PASP) is a kind of green water-treatment chemical, which isrnenvironmentally benign and has good scale inhibiting property. Recently most studies of PASP werernfocused on preparation and application scale inhibitor and only a few on its application as corrosionrninhibitor. The application of PASP as an inhibitor for brass corrosion has not been reported. ACrnimpedance method and polarization curve were used to study the inhibition effect of PASP, Na2WO4rnand the complex of PASP and Na2WO4 for brass corrosion in 3% NaCl solution. The results indicatedrnthat PASP and Na2WO4 both had the inhibition effect. A desirable inhibition effect was shown for brassrncorrosion at 40 mg/L of PASP concentration. The best inhibition effects for Na2WO4 appeared atrn40mg/L for brass corrosion. The highest protection efficiency of the complex of Na2WO4 and PASP atrnthe total inhibitor concentration of 40mg/L for brass is 96.0%, indicating a most significant synergisticrninhibition effect between Na2WO4 and PASP against brass corrosion. The optimum ratio of PASP tornNa2WO4 was 3:1. The results from potentiodynamic polarization curves are in agreement with thosernfrom impedance measurements.