Scale Inhibitor Containing Fluorescent Naphthalene Units Used In Seawater, The Preparation And Performance Thereof

With the freshwater resource runs short of and its price rises day by day, seawater circulation cooling system which is environmental acceptable in the coastal city and region will certainly rapidly develop. The fluorescent tracer method can be conducted on-line and in-real time so that any changes in the amount of treatment polymer being added to the system can be made immediately. The key of the method is the preparation of the fluorescent polymer.A kind of novel water-soluble fluorescent monomer, 2-(methacryloyloxy)-N,N- dimethyl-N- (1-naphthylmethyl)ethanaminium chloride was synthesized firstly using 1-(chloromethyl)naphthalene and dimethylaminoethyl methacrylate in acetone. The experiments optimized technical conditions of synthesis process through single factor experiment and orthogonal experiment. This paper also researched synthesis conditions of the fluorescent acrylic polymer from acrylic acid and fluorescent monomer through orthogonal experiment and evaluated their characteristics of scale inhibition through static inhibition test in seawater.We obtained the main results as following in the process of research:⑴The optimal synthesis conditions of the fluorescent monomer were as follows: reaction temperature was 30℃, the reaction time was 5h, the dosage of acetone was 30mL, the ration of 1-(chloromethyl)naphthalene and dimethylaminoethyl methacrylate(DM) was 1:1, the dosage of inhibitor was 0.5% of DM. The yield may reach 40.8% under the condition.⑵The fluorescent monomer containing naphthalene units had stronger fluorescent properties. The excited and the emitted wavelength of the monomer were 295nm and 340nm, respectively. Relationship between fluorescent intensity and concentration of monomer was linear in deionized water and seawater and the correlation coefficient was 0.9973 and 0.9976, respectively.⑶Acrylic polymer containing naphthalene units, scale inhibitor used in seawater was produced by these components: water, peroxide, acrylic acid and the fluorescent monomer containing naphthalene units. The optimal synthesis conditions of the polymer were as follows: reaction temperature was 95℃, the amounts of the fluorescent monomer, initiator, and adjustment reagent were 0.5%, 15% and 12% according to the weight of the monomers, respectively. The concentration of total monomers was 30%. The scale inhibition rate of the polymer prepared in the orthogonal experiment could reach 87.97% through static inhibition test in seawater, and its scale inhibition performance was comparable with polyacrylic scale inhibitor.⑷The fluorescent characteristics of the acrylic polymer containing naphthalene units were studied. Relationship between fluorescent intensity and concentration of the ponomer were linear in deionized water and seawater. The correlation coefficient in deionized water and seawater was 0.9916. It lays the foundation for the acrylic polymer containing naphthalene units used as a kind of fluorescent tracer scale inhibitor in seawater circulation cooling system and realizingconducted on-line and in-real time.