Copolymerization Of L-glutamic Acid And Maleic Anhydride And Its Performance Of Scale Inhibition

Since the 1960s, the water scale inhibitors experienced a natural water treatment inhibitor, copolymer inhibitor and environmentally friendly scale inhibitor to the development process, in varying degrees, these inhibitors showed some scaling properties, but each had some different shortcomings.With principle of green chemistry, this study designed to L-glutamic acid and maleic anhydride as raw materials, after three-step reaction, the target copolymer of poly epoxy N-maleoyl-L-glutamic acid was obtained, and scale inhibition properties of copolymer were tested and analyzed. The work researched preparation of the poly epoxy N-maleoyl-L-glutamic acid, discussed each step of synthesis conditions and factors, and characterized synthetic products, and finally the scaling properties of polymer were tested.The specific work as follows:1. With L-glutamate and maleic anhydride, N-maleoyl-L-glutamic acid was synthesized. At low temperature, this study designed to synthesis the intermediate product, N-maleoyl-L-glutamic acid. During the test, respectively, the conditions on the synthesis, reaction mechanism and influencing factors were analyzed, and eventually arrived at the optimum synthesis conditions of the target product: L-glutamate/MA molar ratio of 1:1.2, the reaction temperature was 5℃,The pH was controled in the 8 to 9, the reaction time was 5 h, by NMR analysis to determine the target product, the target product generated by post-processing may yield was 97.6%.2. Maked use of hydrogen peroxide oxidizer, sodium tungstate as catalyst, catalytic oxidation N-maleoyl-L-glutamic acid, synthesized the key intermediate material epoxy N-maleoyl-L-glutamic acid sodium. This article researched model reaction and the methodology, by trying, finally reached the optimum synthesis conditions for the target product:N-maleoyl-L-glutamic acid/hydrogen peroxide molar ratio of 1:2, the reaction temperature was 65℃, amount of catalyst for 1% of the N-maleoyl-L-glutamic acid,The pH was controlled at 5 to 7, reaction time was 2h, by NMR analysis, identified as the product of the synthesis after the treatment, The target product was generated and its yield was 97.6%.3. Under the condition of alkali metal catalyst, epoxy N-maleoyl-L-glutamic acid sodium was grouped poly epoxy N-maleoyl-L-glutamic acid sodium. By experiments, the optimum polymer synthesis conditions:epoxy N-maleoyl-L-glutamic acid sodium/ Ca(OH)2=1:0.1, reaction temperature was 90℃, reaction time was 2 hours, the yield was 94.3%.During the test, we focused on water as solvent, efficient catalysts and reaction means, Screened with water as solvent and the alkali metal as catalyst polymerization. Discussed the acylation reaction conditions and the best ratio of raw materials, choiced ethylene oxide reaction methods and catalysts, explored the ratio of polymer materials and the catalyst temperature, Finally the polymer was testing scale performance. Meanwhile, in the synthesis process, we conducted a structural analysis of products, molecular weight, scale and performance testing determination of epoxide conversion. To design an economical, simple and efficient synthetic route of the process, finally, determined molecular weight distribution by molecular weight.Tested product performance. Used a common method:static scale inhibition method. Through its calcium sulfate, calcium carbonate and other calcium scale tests, using titration method and calculate inhibition rate by a formula to explain polymers under a variety of scale inhibition performance test conditions, and compared with other pharmaceutical to response scale inhibitor performance in this case, by the comparison showed that the polymer application better.