Study On The Synthesis And Properties Of Four-element Comb-Type Polyacrylamide

In this paper,a four-element comb-type polyacrylamide with improved solubility,high-temperature resistance,salt and aging resistance was synthesized and evaluated.The kind of polymer can be used in the Tertiary Oil Recovery process and increase the recovery proficiency under critical conditions.Firstly,functional monomer VO1 with good temperature resistance and salt resistance was synthesized by using Williamson ether synthesis method from alkyl phenoxy polyethylene ether and p-chloromethyl styrene.The crude product obtained in the two-step reaction was finally purified with column chromatography.Fourier Transform Infrared spectroscopy?FT-IR?and ¹H Nuclear Magnetic Resonance?¹H-NMR?were used to verified the molecular structure of the functional monomer VO1.The results showed that VO1 was successfully synthesized and its final yield was 58%after purification.Secondly,stable emulsion system suitable for inverse emulsion polymerization reaction was established after the oil phase and emulsifiers were selected,as well as the mass fraction and the amount of the emulsifiers and the ratio of oil to water were determined.The emulsion system was finally determined with liquid paraffin as the oil phase,Span-80 and Op-10 with a mass ratio of 9:1as compound emulsifier which accounts for 8%of the mass fraction of the oil phase,mixture of oil and water with volume ratio of 1:1 as the solvent.Powder-like solid polyacrylamide product could be obtained by using the above reverse phase emulsion.Comb-type polyacrylamide was synthesized with inverse emulsion polymerization method by using acrylamide?AM?as the main raw material.Functional monomer VO1,anionic monomer acrylic acid?AA?,high-temperature and salt resistant monomer 2-acrylamide-2-methylpropane sulfonic acid?AMPS?were introduced into the polymer.K₂S₂O₈ and NaHSO₃ were used as redox reaction initiators.Reaction factors include total monomer concentration,dosage of functional monomer VO1 and AMPS,concentrations of initiators,pH value of aqueous solution,temperature and time of reaction were studied based on the viscosity of the polymer solution.The suitable inverse emulsion polymerization condition was found to be:the total monomer concentration was 30%,the dosages of AMPS,functional monomer VO1 and initiator was 10%,3%and 0.4%,respectively.The pH value of aqueous solution was 8,the reaction temperature was 35?,and the reaction time was 4 h.The yield of the polymerization reaction was 86%and the relative molecular mass of the comb-type polymer obtained was 9.6×10⁶.Structure of the polymer was verified by FT-IR.The polymer was proved to be the aim product.Finally,the solubility,the high-temperature resistance,the salt resistance and aging resistance of the four-element comb-type polymer were investigated.The polymer showed good solubility in water and the dissolution time was less than 3h.The obtained polymer showed better resistances as compared with common partially hydrolyzed polyacrylamide HPAM?molecular weight of 1.8×10⁷?.The viscosity retention rate of the 800 mg/L comb type polymer solution was found to be 75%at80?.The viscosity retention rate was more than 70%when the concentration of NaCl aqueous solution was 3500 mg/L.After 15 days'storage,the viscosity retention rate of the polymer solution was still exceeds 58%.Obviously,the high-temperature resistance,the salt resistance and aging resistance of the synthesized four-element comb-type polymer are all better than that of commonly used HPAM.