Synthesis And Evaluation Of Hydrophobically Associating Polyacrylamide And Ternary Copolymerization Cationic Polyacrylamide

Polyacrylamide is one kind of linear water-soluble macromolecule with the most extensive use,which is applied in the field of petroleum,chemical engineering and water treatment extensively.As an important energy and chemical material,oil is a limited and non-renewable resource.Therefore,we must research and develop the new oil recovery technologies in order to ensure the long-term and stable supply of oil.At present,because of bad tolerance of salt,shear rate and temperature,the application of partially hydrolyzed polyacrylamide which used in China is greatly limited.So the study of hydrophobically associating polyacrylamide was carried out to rasie the salt, shear rate and temperature resistance of oil recovery additive.In this article,the hydrophobically associating polyacrylamide was synthesized by the aqueous solution polymerization and following hydrolysis,selecting acrylamide as hydrophilic monomer,2-Vinylpyridine as hydrophobic monomer, potassium persulfate and azo-compound AM-01 as the complex initiator.The effects of experimental factors such as mass fraction of monomer,initiation temperature,amount of initiator,pH,hydrophobic monomer concentration and additives on the molecular weight of the polymer were studied and then the optimum synthesis conditions were determinded.The obtained optimum reaction conditions were as follows:mass fraction of monomer 30%,initiation temperature 12℃,pH 5.0, hydrophobic monomer 0.4%,initiator AM-01 0.025%and K₂S₂O₈ 0.0025%,additive urea 5%.The molecular weights of polymers were measured by the viscosity method, and the structure of the polymers were characterized by the infrared absorption spectrum and nuclear magnetic resonance.It was investigated how the properties of the polymer solution were affected by the polymer concentration,emperature,salinity and shear rate.The critical associating concentration(CAC) apparesd with the increasing of the polymer concentration.Compared with the partially hydrolyzed polyacrylamide,the hydrophobically associating polyacrylamide had better resistance of salinity,shear rate and temperature.And when shear stress disappeared,the apparent viscosity of hydrophobically associating polyacrylamide solution recovered, showing that the shearing action was reversible.It had important significance in practical applications.At the same time,with the diminution of fresh water resource and focusing on the environmental protection,the flocculants played more and more important roles all over the world.Water-soluble cationic polyacrylamide can be used as efficient flocculants for many disperse systems such as water treatment,paper-making,mineral processing and other fields.It is desirable to synthesize the cationic polyacrylamide with low cost and high performance to improve the flocculating performance of domestic flocculant.Cationic flocculant P(AM-DAC-DMDAAC) was synthesized by aqueous solution polymerization using acrylamide(AM) as the molecular backbone, acryloyloxyethyl trimethyl ammonium chloride(DAC) and dimethyl diallyl ammonium chloride(DMDAAC) as cation group.The obtained optimum reaction conditions were as follows:mass fraction of monomer 30%,initiator temperature 12℃,pH 5.0,cationic monomer concentration 25%,initiator AM-01 0.03%and K₂S₂O₈ 0.003%.The molecular weights of polymers were measured by the viscosity method, and the structure of the polymers were characterized by the infrared absorption spectrum and nuclear magnetic resonance.The polymers' capability of flocculating performance was investigated in waste water.