Study Of Organic Phosphonocarboxylic Acids As Water Stabilizing Agents' Synthesis And Anticorrosion-Antiscaling Properties

The organic phosphoncarboxylic acid water stabilizing agents are widely used in industrial cooling water system, for their excellent anticorrosion and antiscaling properties.Phosphonocarboxylic acid compound 2-phosphonobutane-1,2,4梩ricarboxylic acid(PBTCA), and poly-phosphonocarboxylic acid compound-phosphonated hydrolytic polymaleic anhydride(PHPMA) was synthesized with a new synthetic technique. These two products have been studied with experimental methods. The systematically experimental study of synthetic products in corrosion and scale inhibition properties has been done.The 2-phosphonobutane-l,2,4-tricarboxylic acid(PBTCA) was synthesized through 3 reactive steps by using fumaric diethylester, ethyl phosphite, and ethyl acrylate as raw material and using ethylenediamine as catalyzer. The synthesis of phosphonoanted hydrolytic polymaleic anhydride(PHPMA) can be completed with 2 steps by using water as solvent, maleic anhydride and phosphorous acid as raw material, F^C^ as causer, FeCl? as catalyzer, at temperature about llO'C.The molecular structure and composition were analyzed by using IR spectrum, mass spectrum and high performance liquid chromatography(HPLC).A rotary hanged weight losing method was used to measure the anti corrosion properties of the synthetic products in different dosages. The result indicate: 20mg/l of PBTCA shows significant effect of anticorrosion. If it is used in pretreatment, 4mg/l of PBTCA was enpugh to reach the same effect. Furthermore, Zn2+ greatly enhanced the anticorrosion effect of anticorrosion of PBTCA. 50mg/l of PHPMA shows great effect of anticorrosion. When it is used in pretreatment film, 10mg/l of was enough to get the same effect. Especially, Ni2+ can enhance the anticorrosion of PHPMA.The antiscaling property of synthetic products was studied by using method ofdynamic bubble. Especially, the kinetic study of inhibition mechanism of PBTCA on CaCO3 scale was made through experiment. It is found that the absorption of PBTCA on the crystal surface accords with the characters of Langmuir model, which is a kind of single molecule layer sorption. For synthesis PHPMA product, its scale inhibition properties was experimentally investigated in different dosage of agent, value of PH , and concentration of calcium ion.The studied results show: the synthetic two products have excellent anticorrosion and antiscaling properties, so these two products can be used in industrial cooling water treatment system.