Synthesis And Research On Scale And Corrosion Inhibitor Of Copolymer Containing Phosphine

In the circulating cooling water system,in order to reduce the economic loss caused by scale and corrosion of equipment and pipelines,the development of scale and corrosion inhibitors research is highly favored.In this paper,based on previous research,a telenyl unsaturated phosphonic acid monomer（HPDP）was produced from phosphorus trichloride and acrylic acid.Using ammonium persulphate as an initiator,HPDP was copolymerised with maleic anhydride and sodium allyl sulfonate in aqueous solution to obtain the multifunctional hydrophilic copolymer scale inhibitor MA-SAS-HPDP.The optimal synthesis conditions of MA-SAS-HPDP were explored by orthogonal tests,focusing on the effects of conditions such as the amount of initiator,the ratio of monomers,polymerization temperature and reaction time on the calcium carbonate scale resistance of MA-SAS-HPDP.The monomers and polymers were characterized by ¹H?NMR and FT-IR,and the viscoaverage molecular weight of the polymers was determined by Ustler viscometer.The scale inhibition performance（calcium carbonate,calcium sulfate and calcium phosphate）of MA-SAS-HPDP was studied by static scale inhibition method.The effects of external conditions,such as test temperature,test time,p H and Ca²⁺concentration,on the ability of the polymer to resist calcium carbonate scale were investigated separately.The corrosion inhibition performance of the polymer was explored by rotating hanging plate method.The scale inhibition and corrosion inhibition properties of the polymer were compared with commercially available scale inhibitors（polyacrylic acid,hydrolyzed polymaleic anhydride and hydroxyethylidene diphosphonic acid）.The scale inhibition mechanism of MA-SAS-HPDP was investigated by scanning electron microscope（SEM）and X-ray diffraction（XRD）.The experimental results show that MA-SAS-HPDP is a new type of high-efficiency scale and corrosion inhibitor,and its scale and corrosion inhibition performance is significantly better than these three commercially available scale inhibitors.MA-SAS-HPDP can change the morphology and crystal shape of calcium carbonate crystals.The interaction of MA-SAS-HPDP molecules with calcite crystalline surfaces and carbon steel surfaces was simulated by molecular dynamics simulation,and the mechanism of scale inhibition of calcium carbonate and corrosion inhibition of carbon steel by MA-SAS-HPDP was investigated by combining radial distribution functions.The simulation results are in full agreement with the experimental results.The scale inhibition mechanism of MA-SAS-HPDP is mainly through chelating solubilization,lattice distortion and dispersion.The phosphinyl group in MA-SAS-HPDP molecule can play a positive role in corrosion inhibition,and lone pair in P atom can form coordination bond with metal surface to achieve chemisorption,thus slowing down the corrosion of metals.