Preparation And Performance Studies Of Imidazoline Corrosion Inhibitor And Polyaspartic Acid

Green chemistry and its application technology have become the important contents of environmental protection and preventing pollution. Synthesis of imidazoline-type inhibitior, which has a simple preparation, high efficiency and nontoxicity, polyaspartic acid(PASP), which has nontoxicity and biodegradability have become the frontier researches in the field of industrial cooling water and petrochemical engineer.Water soluble imidazoline inhibitor had been synthesized by a two-step vacuum dehydration method using fatty acid such as oleic acid and lauric acid and amine such as diethylene triamine and N-(2-hydroxyl-ethyl)-ethylenediamine by former investigator of our group. But its corrosion inhibition efficiency was low and the performance wasn't optimistic after long time. Propiolic alcohol, butynediol and hexadecyl trimethyl ammonium bromide(CTAB) were used to compound with imidazoline-type inhibitors. Polyaspartic acid(PASP) was synthsised by vacuum polymerization method using maleic anhydride and ammonia water as precursors. Enviromental friendly corrosion and scale inhibitor was prepared successfully using imidazoline inhibitor and polyaspartic acid.The structures of imidazoline intermediates and polysuccinimide, corrosion inhibition performance of imidazoline-type inhibitors, scale inhibition performance of polyaspartic acid were characterized by infrared spectrum analysis, Tafel polarization curve, SEM, energy spectrum analysis, static weight-lossing method, EDTA chelatometry and spectrophotometry.The results show that the compounding of propiolic alcohol improves the corrosion inhibition efficiency and reduces the corrosion rate in large degree, effect of butynediol is the second and CTAB hardly improves the inhibition performance. Inhibition efficiency of imidazoline can achieve above 99% under low concentration after compounding with propiolic alcohol. The imidazoline-type inhibitors compounding with propiolic alcohol inhibit corrosion by forming a much more compact and uniform adsorbed inhibitor film on the metal surface, which still have high inhibition efficency at lower concentration after a longer time. Polyaspartic acid adapts to high concentration of calcium ion and high temperature water systerm. It inhibites not only calcium carbonate scale but also calcium sulfate scale. It also has decentralization against ferric iron oxide and a certain corrosion inhibition performace. The addition of PASP can change the crystal type of calcium carbonate and has obvious inhibition efficiency on calcite. The corrosion and scale inhibitor, which is synthesized successfully by imadaz-oline inhibitor and polyaspartic acid, will have a extensive application prospect in petrochemical engineering, metallurgy and generate electricity industry.