Synthesis and properties for a acrylamide tetra-copolymer sulfonate

With NaHSO3-(NH4)2S2O8 as initiator,the quadripolymer AM/MA/NVP/SAS was polymerized in aqueous solution,using acrylamide(AM),maleic anhydride(MA),N-Vinyl-2-pyrrolidone(NVP)and sodium allyl sulfonate(SAS)as monomer.The optimized conditions were build:AM/MA=6:2(mol),the initiator:0.5 wt%,temperature:45℃ and the reaction time:5 h,pH:8.The AM/MA/NVP/SAS was identified by IR spectra.It was found that the apparent viscosity of the copolymer can be kept around 20 mPa·s,while the viscosity retention rate of about 30%when the concentration of NaCl,CaCl2 in the 10000 mg/L,3000 mg/L solution,respectively.