Synthesis And Corrosion Inhibition Of Starch Graft Copolymer

In order to protect metal from corrosion,it is a simple and efficient way to add corrosion inhibitor.With the improvement of people's environmental awareness,some toxic and harmful inhibitors are restricted to use.Therefore,the synthesis of green environmental protection inhibitors is an important direction of current research.Starch graft copolymers,as a new generation of cheap and easy to obtain,high efficiency and friendly green corrosion inhibitor,can be synthesized by grafting different monomers.In this paper,two kinds of starch graft copolymers were synthesized by redox reaction system.The corrosion inhibition performance of starch graft copolymers to zinc in acid medium was tested,and the application in mercury free paper was explored.Firstly,starch acrylamide graft copolymer(St-g-PAM)was synthesized.The structure of St-g-PAM was characterized by infrared spectroscopy.The corrosion inhibition of St-g-PAM for zinc in 1.0 mol/L hydrochloric acid solution was investigated by weight loss,electrochemistry,scanning electron microscopy(SEM)and atomic force microscopy(AFM).When the concentration of St-g-PAM was 50 mg/L,the inhibition rate was95.66%,which indicated that St-g-PAM has good inhibition performance.The adsorption thermodynamics and kinetics of St-g-PAM were systematically calculated to analyze the adsorption behavior and corrosion inhibition mechanism of St-g-PAM on zinc surface.Secondly,starch methacryloyloxyethyl trimethylammonium chloride graft copolymer(St-g-PDMC)was synthesized and characterized.The corrosion inhibition of St-g-PDMC for zinc in 1.0 mol/L hydrochloric acid solution was investigated by weight loss method,electrochemical method,contact angle and X-ray photoelectron spectroscopy(XPS).When the concentration of St-g-PDMC was 50 mg/L,the inhibition rate was 95.42%.The concentration of inhibitor,temperature and soaking time all affect the inhibition effect of zinc in hydrochloric acid.The results of weight loss method and electrochemical method were consistent,which showed that St-g-PDMC can effectively inhibit the corrosion of zinc in acid medium.Finally,the starch graft copolymers with better corrosion inhibition performance were applied to the pulp paper instead of the modified starch in the original pulp,and had a certain corrosion inhibition.A new green mercury free pulp paper was prepared according to the best formula,and it was in accordance with the standard requirements of QB/T 2303-2008.