Study On Amphiphilic Block Tercopolymer Of P(AM/NaAMPS/St) For EOR

The copolymerization of acrylamide(AM) and sodium 2-acrylamido-2-methyl-propane-sulfonate(NaAMPS) was carried in aqueous solution and a series of copolymer P(AM-co-NaAMPS) with varied composition were first prepared in this investigation. The structure and composition of the copolymers were characterized by FTIR spectrum and element analysis.The viscosities of the copolymers were determined using Ubbelohde viscometer, and the intrinsic viscosities by which molecular weight can be indicated relatively were determined with the method of dilute extensional method. At the same time the Huggins constants by which the interaction between polymer and solvent can be displayed were also obtained. The apparent viscosities of aqueous solutions and brine of the copolymers were measured using a low shear rotational viscometer, and thermal stability experiment was carried and the maintaining ratios of viscosity at high temperature were measured, the relationships between the structure and composition and the properties of the copolymers P(AM-co- NaAMPS) were studied emphatically, which proffers some basics of theorem for tercopolymer of acrylamide. Then, the copolymerization of AM, NaAMPS and styrene(St) was carried in microemulsion madium, and tercopolymer P(AM/NaAMPS/St) containing strong anionic group - S03- and hydrophobic association block PSt was synthesized. The structure and composition of the copolymer were characterized by FTIR spectrum, UV spectrum and complex reaction conductometric titration was founded to determinat the content of sulfonate monomer in water-soluble copolymer . The viscosities of the copolymers were determined using Ubbelohde viscometer, and the intrinsic viscosities by whichmolecular weight can be indicated relatively were determined with the method of dilute extensional method. The apparent viscosities of aqueous solutions and brine of the copolymers were measured using a low shear rotational viscometer and the rheological property of the copolymer was investigated. The hydrophobically associating property and influence of ionic groups on the hydrophobic association property were investigated. Besides, the relationships between the rheological property and the salt resistance of the copolymer to the microstructure of the macromolecular chains were examined emphatically. The experimental results are as follows. After incorporating strong anions and hydrophobic blocks at the same time in the backbone of polyacrylamide, the viscosity of the copolymer aqueous solution will increase obviously under coordination of electric viscosity of ions and hydrophobic association property of hydrophobic blocks, and the salt resistance of the copolymer will increase evidently under the combining of strengthening hydrophobic association by salt and greater tolerating salt of strong anions; Tercopolymer P(AM/NaAMPS/St) containing strong anionic group -SO3" and hydrophobic association block PSt was obviously improved in some properties of copolymer for Enhanced Oil Recovery (EOR); The hydrophobic association property of block PSt is weakened and the critical associating concentration of the copolymer is increased due to existing of strong anionic groups in macromolecular chains.