Study On Corrosion Inhibition Of Polyaspartic Acid And Polyepoxysuccinic Acid

With green Chemistry, people paid more attention to environment. Environmentally Benign corrosion scale inhibitor, such as polyaspartic acid （PASP） and polyepoxysuccinic acid （PESA）, has become the focus in the fields of water treatment in the last decade.Polyaspartic acid and polyepoxysuccinic acid are new biodegradable corrosion and scale inhibitors free of phosphorous （P）. By the method of weight-loss and some electrochemical methods（ polarization curve and electrochemical resistance curve）, we studied the corrosion inhibition on carbon steel of polyaspartic acid combined with polyepoxysuccinic acid, organophosphates, zinc stabilizer, sodium gluconate （Glu） and zinc sulfate in tap water in Shanghai. The corrosion inhibition behavior of PASP and compound corrosion inhibitors was characterized by polarization curve and electrochemical resistance curve. The adsorption of PASP, on silver and ferric surface was studied by surface-enhance Raman spectrum （SERS）.The experimental results indicated that the addition of low levels of PASP and PESA proves some corrosion inhibition. PASP is a kind of anodic corrosion inhibition The combined corrosion inhibitors were of excellent corrosion inhibition to carbon steel; they play the anti-corrosion mechanism as an anode and these formulas are of promise in applications. Formular consisted by PASP,PESA,HPAA,Glu,Zn²⁺ or PASP,PESA,HPMA,Glu,Zn²⁺ worked well under standard water, the corrosion inhibition rate were below 0.1mm·a^-1 and 0.05 mm·a^-1 respectively.SERS study indicated that PASP from a resist film through carboxyl and amidoto keep the oxygen and other ions away from ferric surface. The electrochemical method has a advantage of fast easy and economical, it can reduce workload of weight-loss and estimate the reliability of two similar formular.