Preparation of polyacrylamide “water-in-water” emulsion by dispersion polymerization

Water-soluble polyacrylamide dispersion was prepared by making use of the dispersion polymerization of acrylamide in(NH4)2SO4aqueous medium.The effects of(NH4)2SO4concentration,relative molecular weight of poly(methylacryloylxyethyl trimethyl ammonium chloride)(denoted as PDMC)and sodium formate dosage on the dispersion stability of as-prepared polyacrylamide dispersion were investigated.Results indicate that stable polyacrylamide dispersion can be obtained under the optimal reaction condition involving PDMC with an average relative molecular weight of 8.02×105 and 20.9%(mass fraction)of(NH4)2SO4in the absence of sodium formate.Resultant polyacrylamide polymer obtained under the optimal reaction condition has a relative molecular weight of 1.12×106.