Study On The Synthesis And Application Of Low Phosphorus Corrosion Inhibitor

In this paper, the target product glyphosine and N-phosphonomethyl iminodiacetic acid was synthesized with glycine、phosphite、formaldehyde and iminodiacetic acid、phosphite、formaldehyde. The effect of reactant mole ratio、reaction temperature、reaction time and acidity on the yield of target product was studied through single factor experiment and orthogonal experiment. The best processes were confirmed:the mole ratio of glycine、phosphite and formaldehyde was 1: 2: 3、reaction temperature was 120 ℃、reaction time was 3.5 h、the mole ratio of phosphite and hydrochloric acid was 1: 1.5;the mole ratio of iminodiacetic acid、phosphite and formaldehyde was 1: 1: 1.25、reaction temperature was 120 ℃、reaction time was 4 h、the mole ratio of phosphite and hydrochloric acid was 1: 1.5. The target product were characterized by melting point test、infrared spectrum analysis、nuclear magnetic resonace spectrum analysis and elemental analysis after crystallization purification.The effect of pH、temperature and concentration on the corrosion inhibition performance of target product was studied by polarization curve method and electrochemical impedance spectroscopy. The target product were compared with the similar phosphonic acid ATMP(amino trimethylene phosphonic acid). Besides,the corrosion inhibition performance of the mixture of target product and triethanolamine was studied.At last, the corrosion inhibition performance of glyphosine and N-phosphonomethyl iminodiacetic acid was compared,and the corrosion inhibition performance of their mixture was also studied.