The Preparation,Enlarged Experimentation And Application Of Cationic Polyacrylamide Water-in-water Emulsion

In our country,the water pollution is very serious,cationic polyacrylamide is widely applied in wastewater treatment for its excellent water treatment effect,and it can also be used in oil field exploitation,pulp and paper,sludge dewatering and other fields,so it occupies an important position in the national economy.Cationic polyacrylamide includes hydrosol,dry powder,inverse emulsion,water-in-water emulsion and other product types.Among them,with the advantages of fast dissolution rate,high efficiency,easy to use,safety,environmental protection and so on,water-in-water emulsion product has become the new direction of the research,development and production of cationic polyacrylamide.The research content of this paper is divided into three parts.Part one:using aqueous dispersion polymerization technology,polymethyl acryloyloxyethyl trimethyl ammonium chloride?PDMC?was added as a dispersion stabilizer in aqueous solution of ammonium sulfate??NH₄?₂SO₄?,and water-soluble azo compound?V-50?was used as a initiator to initiate the free radical polymerization of monomers acrylamide?AM?and methacryloyloxyethyl trimethyl ammonium chloride?DMC?,the cationic polyacrylamide?CPAM?water-in-water emulsion was successfully prepared.The effects of PDMC molecular weight and concentration,the amount of V-50,?NH₄?₂SO₄concentration,the monomer total mass concentration and the proportion,the system pH value,stirring rate,reaction temperature,complexing agent concentration,solubilizer concentration and reaction time on the polymerization were systematically explored.The particle morphology of the emulsion,the polymer molecular structure and properties were characterized,analysed and determined through FTIR,¹H NMR,polarized light microscopy,laser scattering particle size analyzer,Ubbelohde viscometry and rotation viscometer,and the optimized synthesis conditions were achieved.Part two:on the basis of the pilot study,the 10 L double glass-layer reactor was used for the enlarged experimentation of CPAM water-in-water emulsion to optimize its synthesis conditions,and a optimized synthesis scheme was obtained.The repeated enlarged experimentation proved the feasibility of the optimized synthesis scheme.The apparent viscosity of the obtained emulsion was about 190 mPa·s,the dissolution time was less than 1min,the relative molecular weight was about 2.25×10⁶ g/mol,and the monomer conversion rate was above 98%.Part three:kaolin was used to simulate wastewater,and the flocculation experiment was performed with the prepared CPAM water-in-water emulsion.The effects of flocculant dosage,flocculant molecular weight,cationic degree,stirring time,stirring rate,pH value and sedimentation time on flocculation were investigated through single factor experiments.The optimum flocculation process conditions were obtained,the turbidity removal rate of kaolin suspension could reach 90.61%⁹7.24%.