The Scale Inhibitor Containing Fluorescent Monomer

In recent years, the circulating water treatment system is mainlyadopted the fluorescence to monitor content of water treatment agent inthe cooling water, so as to realize the water treatment system of on-linedetection and automatic control purposes. It must be uesd tracer typewater treatment agent in order to detect expediently. At present, thetracer type water treatment agent mainly through the monomercopolymerization, and in the preparation process, fluorescent monomersynthesis is essential one step. This thesis mainly discuss preparing thetracer type scale inhibitor which can play the role of fluorescent tracerand control water treatment agent in circulating cooling water. In thepaper, a novel water soluble fluorescent monomer（Ⅲ） has beensynthesized from4-bromo-1,8-naphthalic anhydride andethylenediamine through synthesis of three-step.The acrylic acid copolymer containing fluorescent group1hasbeen prepared by fluorescent monomer and acrylic acid. Thepolymerization is initiated by per sulfate ammonium and regulated by2-propanol in aqueous solution. By static method, the scale inhibitionratio of CaCO₃was determined. The optimum conditions of synthesisare determined by experiments as follows: n（fluorescent group）:n（AA）＝1:3, the reaction temperature is90℃, the reaction time is2.5h.Polymerization conditions were investigated for the effect of inhibitionof the copolymer. The relationship of fluorescent intensity and concentration of the copolymer is linear, and the correlation coefficient（R） was0.9648, the lower limit of detection is6.8×10^-4mg/L. Theresults of fluorescence showed that approach to the synthesis of thenover fluorescent monomer can significantly reduce the detection limitof the copolymer. The scale inhibition ratio of CaCO₃was88.2%whenthe copolymer concent ration was20mg/L.The copolymer of containing fluorescent group2has beenprepared by fluorescent monomer, acrylic acid（AA） and maleicanhydride（MA）. Polymerization conditions were investigated for theeffect of inhibition of the copolymer. The effects of the copolymer onfluorescence and scale inhibition are studied. The relationship offluorescent intensity and concentration of the copolymer is linear, andhe correlation coefficient （R） was0.9985, the lower limit of detection is1.0×10^-2mg/L. By the static method, the scale inhibition ratio of CaCO₃was93.5%when the copolymer concent ration was20mg/L. Thecapacities of dispersing iron oxide are pretty good. It is found byelectronic microscopy that it has obvious effect on CaCO₃scale withregard to its dispersion and crystal lattice distortion capacities.The copolymer of containing fluorescent group3has beenprepared by fluorescent monomer, acrylic acid（AA） and sodiumallylsulfonate（SAS）. Polymerization conditions were investigated forthe effect of inhibition of the copolymer. The effects of the copolymeron fluorescence and scale inhibition are studied. The relationship offluorescent intensity and concentration of the copolymer is linear, andhe correlation coefficient （R） was0.9934, the lower limit of detection is3.9×10^-2mg/L. By the static method, the scale inhibition ratio of CaCO₃was90.6%and Ca3（PO4）2was86.2%when the copolymer concentration was20mg/L. The capacities of dispersing iron oxide are prettygood.In the paper, three kinds of polymer was synthesized. When theyare in a relatively low concentration,he relationship of fluorescentintensity and concentration of their is linear, the limit of detection islower, scale inhibition efficiency is high, and dispersion performance is good. These scale inhibitor of water treatments has favourabledispersion performance, application prospects and market value.