Solution properties and flocculation of hydrophobically associating cationic fluorinated polyacrylamide

The hydrophobically associating cationic fluorinated polyacrylamide (CFPAM), modified with fluorinated acrylate, 2-(perfluorooctyl)ethyl acrylate (FEA), has been newly synthesized, by free radical micellar copolymerization in aqueous solution. The solution properties of these polymers were investigated in details in this study. In addition, the flocculation of CFPAM was also evaluated. The results showed that there were strong hydrophobic associations in the CFPAM aqueous solution. The addition of NaCl resulted in an increase of solution viscosity, which indicated the good salt-resistant performance of CFPAM. The polymers also exhibited excellent property of temperature and shearing tolerance. Furthermore, the polymer showed high surface activity. At the same time, its flocculation properties were evaluated with kaolin suspensions using a standard jar test. All the results demonstrated the superiority of the cationic fluorinated polyacrylamide as a flocculant.     

疏水缔合聚丙烯酰胺固沙剂的制备及性能研究

研发了一种具有良好固沙性能的水溶性固沙剂,该固沙剂是一种可持续的固沙材料。首先就疏水缔合阳离子聚丙烯酰胺-腐植酸的化学固沙机理讨论了固沙剂与沙粒之间的粘附力。研究了凝固机理,测试了固沙剂的固化时间。然后研究了固沙剂的渗透性能。通过扫描电子显微镜(SEM)分析了固沙层的微观结构。在不同浓度的固沙剂条件下,研究了固沙层的抗压强度。最后,通过模拟风机实验研究了固沙层的抗风蚀性。结果表明,固沙剂水溶液与沙粒表面具有极好的亲和力,并且固沙剂与沙粒之间的粘附力主要是氢键作用和静电作用。固沙层的固结时间随着温度和浓度的增加而降低。     

Intrinsic viscosity,rheological property,and oil displacement of hydrophobically associating fluorinated polyacrylamide

The surface‐active polymer (FPAM) was synthesized by free‐radical polymerization of acrylamide (AM), 2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid (AMPS) and N ‐dodecyl‐N ‐perfluoro octane sulfonyl acrylamide (AMPD), which was prior prepared by reacting dodecylamine, perfluoro‐1‐octanesulfonyl fluoride, and acryloyl chloride. Parameters affecting the intrinsic viscosity ([η]) and apparent viscosity (η) of FPAM, such as reaction temperature, AMPD concentration, AMPS concentration, monomer concentration, initiator concentration, and pH were examined. Apparent viscosity and interfacial tension (IFT) of FPAM solution were evaluated. Subsequently, temperature tolerance and shear tolerance were investigated by comparing with hydrolyzed polyacrylamide (HPAM), and results indicated that the FPAM displayed better performances than HPAM. FPAM can reduce the IFT between crude oil/water, and the IFT values are around at 2.91 and 3.9 mN m^?1 corresponding to FPAM and HPAM/FC‐118. The sandpack model oil displacement experiment showed that water flooding can further increase the oil recovery to 15.01% (FPAM), compared with 9.26% oil recovery for HPAM, and 10.99% oil recovery for HPAM/FC‐118. The glass micromodel techniques for studying enhanced oil recovery get a good result and provide a useful reference for understanding the displacement behaviors in polymer flood process. It could be concluded that the introduction of fluorinated groups in the polymer chain was helpful in enhancing the oil displacement efficiency. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44672.     

疏水缔合型阳离子聚丙烯酰胺的合成及絮凝性能

以甲基丙烯酸三氟乙酯(TFEMA)为疏水单体、丙烯酰胺(AM)为主单体、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为阳离子单体,以过硫酸铵和亚硫酸氢钠为复合引发剂,采用自由基胶束聚合法合成了共聚物P(AM-DMC-TFEMA)。分别考察了反应温度、引发剂用量、单体总质量分数及反应时间对P(AM-DMC-TFEMA)的产率及阳离子度的影响。确定较佳工艺条件为:反应温度65℃,引发剂用量占单体总质量的2%,单体总质量分数26%,反应时间3 h。采用红外光谱(FT-IR)、核磁共振氢谱(~1H NMR)和环境扫描电镜(ESEM)对其结构进行了表征。同时考察了P(AM-DMCTFEMA)对硅藻土悬浮液的絮凝效果,结果表明,其对硅藻土具有良好的絮凝效果,絮凝时间仅为20 s,合成的共聚物上清液透过率为97.31%。     

疏水缔合聚合物在搅拌槽中的溶解特性

Enhanced oil recovery (EOR) by means of polymer flooding is an important technology for the strategic development of offshore oilfields in China. Hydrophobically associating polyacrylamide (HAPAM) has been recently proposed as a new flooding agent. The solubility of HAPAM is low, which is the bottleneck for further improving the oil recovery through polymer flooding in offshore oilfield. Stirred tanks have been used on offshore platforms to enhance HAPAM dissolving. But there is little literature on the study of HAPAM dissolving characteristics in stirred tanks. In this paper, effects of temperature, salinity, stirring speed, impeller type and stirring method on the dissolution of HAPAM are reported. The experimental results manifest that the dissolving rate of HAPAM increases with temperature and stirring speed, but the viscosity of the polymer solution decreases. There is an optimal range of salinity for polymer dissolving. Combining the operation mode of up-pumping with varying stirring speed, hydrofoil impeller can accelerate the dissolution of HAPAM and maintain a high solution viscosity.     

两性疏水缔合聚丙烯酰胺的室内性能研究

以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和一种疏水长链烷基烯丙基氯化铵(M-18A)为单体,以溶剂油为油相,采用反相乳液聚合法合成一种两性疏水缔合聚丙烯酰胺增稠剂(AP-AM18)。在最佳合成条件下,利用核磁共振氢谱(~1H NMR)、红外光谱(FTIR)、X-射线衍射(XRD)和热重分析仪(TGA)对AP-AM18进行了表征。红外光谱结果表明,单体发生聚合;XRD图显示其具有非晶体结构;对聚合物AP-AM18的热稳定性分析发现,分解温度超过500℃后,样品质量基本不变,表明聚合物具有良好的耐温性;对AP-AM18进行增稠、耐盐性能测试发现,随着浓度的升高,表观黏度逐渐上升,当浓度为2%时,聚合物AP-AM18在清水中的表观黏度达到893 m Pa·s,在5×10~4mg/L矿化水中,表观黏度达到391 m Pa·s,表明其具有较好的增稠、耐盐性能。     

两性疏水缔合聚丙烯酰胺的室内性能研究

以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和一种疏水长链烷基烯丙基氯化铵(M-18A)为单体,以溶剂油为油相,采用反相乳液聚合法合成一种两性疏水缔合聚丙烯酰胺增稠剂(AP-AM18)。在最佳合成条件下,利用核磁共振氢谱(¹H NMR)、红外光谱(FTIR)、X-射线衍射(XRD)和热重分析仪(TGA)对AP-AM18进行了表征。红外光谱结果表明,单体发生聚合;XRD图显示其具有非晶体结构;对聚合物AP-AM18的热稳定性分析发现,分解温度超过500℃后,样品质量基本不变,表明聚合物具有良好的耐温性;对AP-AM18进行增稠、耐盐性能测试发现,随着浓度的升高,表观黏度逐渐上升,当浓度为2%时,聚合物AP-AM18在清水中的表观黏度达到893 m Pa·s,在5×101H NMR)、红外光谱(FTIR)、X-射线衍射(XRD)和热重分析仪(TGA)对AP-AM18进行了表征。红外光谱结果表明,单体发生聚合;XRD图显示其具有非晶体结构;对聚合物AP-AM18的热稳定性分析发现,分解温度超过500℃后,样品质量基本不变,表明聚合物具有良好的耐温性;对AP-AM18进行增稠、耐盐性能测试发现,随着浓度的升高,表观黏度逐渐上升,当浓度为2%时,聚合物AP-AM18在清水中的表观黏度达到893 m Pa·s,在5×10⁴mg/L矿化水中,表观黏度达到391 m Pa·s,表明其具有较好的增稠、耐盐性能。     

Solution properties of ionic hydrophobically associating polyacrylamide with an arylalkyl group

Copolymers of acrylamide, 2‐acrylamide‐2‐methylpropanesulfate (AMPS), and hydrophobic monomer N‐arylalkylacrylamide (BAAM) were synthesized by free‐radical micellar copolymerization. The effects of the copolymer, BAAM, AMPS, and NaCl concentrations and the pH value on the apparent viscosity of the copolymers were studied. The solution viscosities increased sharply when the copolymer concentration was higher than the critical associating concentration. The apparent viscosities of aqueous solutions of poly(N‐arylalkylacrylamide‐co‐acrylamide‐co‐2‐acrylamide‐2‐methylpropanesulfate) (PBAMS) increased with increasing BAAM and AMPS concentrations. PBAMS exhibited good salt resistance. With increasing pH, the apparent viscosities first increased and then decreased. Dilute PBAMS solutions exhibited Newtonian behavior, whereas semidilute aqueous and salt solutions exhibited shear‐thickening behavior at a lower shear rate and pseudoplastic behavior at a higher rate. Upon the removal of shear, the aqueous solution viscosities recovered and became even greater than the original viscosity, but the salt solution viscosities could not recover instantaneously. The elastic properties of PBAMS solutions were more dominant than the viscous properties, and this suggested a significant buildup of a network structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 316–321, 2005     

Dilute solution properties of hydrophobically associating polyacrylamide: fitted by different equations

In this paper six different equations were used to fit the data of dilute solution of both nonionic (PBAM3) and ionic (PBAMS) hydrophobically associating polyacrylamide with and without the addition of NaCl. The results showed that Fedors equation was the most accurate equation to describe the dilute solution properties of these kinds of polymers. The lower value of the polymer concentration parameter (C_m) in Fedors equation was corresponded to the higher value of the constant k in Schulz-Blaschke equation for PBAM3 system. Two types of polymers had anti-polyelectrolyte effect. In dilute solution the PBAMS polymer chains had a more extended conformation than those of PBAM3 due to the existence of ionic groups.     

Preparation and performance evaluation of hydrophobically associating polymer anti-water channeling agent for oil well cement

The channeling resistance of cement slurry is one of the critical factors related to cementing quality, especially in the cementing of adjustment well. Due to the complex pressure layer and large pressure fluctuation, the annular channeling problem is easily caused by water invasion. Using 2-acrylamide-2-methyl propane sulfonic acid (AMPS), acrylamide (AM), maleic anhydride (MA), acrylic ester 18(St) as raw materials, we prepared a hydrophobic associative polymer (SMAL) by free radical micellar polymerization. The synthetic products were characterized by IR, NMR, and SEM, and the evaluated engineering application performance. The results showed that SMAL achieved the expected synthesis purpose. Compared with the water channeling pressure of 0.1 Mpa for blank cement slurry, the water channeling pressure of SMAL cement slurry reaches 5.3 Mpa, which significantly improves the anti-water channeling ability of cement slurry. After adding SMAL, the 14d flexural strength of cement stone was also increased from 7.7 to 8.3 MPa, which had no adverse effect on cement slurry's rheological property.     

疏水缔合三元共聚物破乳剂的合成及破乳性能评价

以AM/BM/DMC为单体(质量配比为1:0.04:1,单体总质量浓度35%),采用水溶液聚合法,引发剂加量1%,反应温度25℃,反应时间4 h,合成了AM-BM-DMC疏水缔合三元共聚物破乳剂,对其在不同浓度、不同温度、不同时间下的破乳性能进行评价。结果表明,通过水溶液聚合方法合成的疏水缔合三元共聚物破乳剂在常温(25℃)下,对O/W型乳状液具有较好的破乳能力,脱出水色清,脱水速度快,脱水率高,可达90.8%。其破乳的温度范围为20～40℃,无需加热设备,适合于现场应用,是一种具有潜力的新型破乳剂。     

一种含甜菜碱型单体的缔合型稠化剂的合成及性能评价

以甲基丙烯酰氧乙基二甲基胺(DM)和1,3-丙磺酸内酯为原料,合成了3-(2-甲基丙烯酰氧乙基二甲胺基)丙磺酸盐(DMAPS)甜菜碱型单体;以DMAPS单体、丙烯酰胺、疏水单体进行三元共聚,后水解,得到一种缔合型稠化剂。对其抗温抗盐,流变性,粘弹性进行了评价。结果表明,稠化剂具有良好的溶解性、抗温抗盐性、粘弹性。     

一种含甜菜碱型单体的缔合型稠化剂的合成及性能评价

以甲基丙烯酰氧乙基二甲基胺(DM)和1,3-丙磺酸内酯为原料,合成了3-(2-甲基丙烯酰氧乙基二甲胺基)丙磺酸盐(DMAPS)甜菜碱型单体;以DMAPS单体、丙烯酰胺、疏水单体进行三元共聚,后水解,得到一种缔合型稠化剂。对其抗温抗盐,流变性,粘弹性进行了评价。结果表明,稠化剂具有良好的溶解性、抗温抗盐性、粘弹性。     

Studies on the self‐assembly behavior of the hydrophobically associating polyacrylamide

Contrasted with partially hydrolyzed polyacrylamide (HPAM), the self‐assembly behavior and microstructure of hydrophobically associating polyacrylamide (HAPAM) in aqueous solution have been studied by means of fluorescence spectrum, transmission electron microscopy (TEM), atomic force microscope (AFM), and apparent viscosity test in this article. The fluorescent probe analysis indicates that the HAPAM molecules will form associating aggregates in pure water. The results show that HAPAM can easily self‐assemble to form an aggregate by hydrophobic driving force in dilute aqueous solution. The association of hydrophobic groups of the HAPAM causes the formation of supermolecule, so there are associating aggregates formed at very low concentration and then leads to the formation of network at a higher concentration. TEM and AFM measurements show that a distinct network structure has been formed in 1000 mg L^?1 of HAPAM solution, indicating the strong association of hydrophobic groups. These results are consistent with the viscosity measurement and reveal that the excellent viscosification of HAPAM is due to the association of hydrophobic groups in the aqueous solution. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Synthesis,characterization, and properties of novel hydrophobically associating fluorinated copolymers for DNA delivery

Novel fluorinated associative copolymers poly(ethylene glycol)-b-poly(2-(perfluorohexyl)ethyl methacrylate (PFHEMA)-co-3-[N-(2-methacroyloylethyl)-N,N-dimethylammonio]-propane sulfonate (DMAPS)) (PEG-b-PPFHEMA/PDMAPS) were prepared as a type of non-viral gene vector. The series of PEG-b-PFHEMA/DMAPS with different molecular weights and compositions were characterized by gel permeation chromatography–multi-angle light scattering, ¹H NMR, ¹⁹F NMR, and elemental analysis. The interactions of the copolymers with calf thymus DNA and the morphologies of the resulting complexes were studied by fluorescence spectroscopy, dynamic light scattering, and transmission electron microscopy. In addition, the DNA–polymer interaction, as determined by the gel retardation assay, and the low cytotoxicity of PEG-b-PPFHEMA/PDMAPS demonstrated that these copolymers have good DNA binding capacity and potential for high performance in the practical application of DNA delivery.     

疏水缔合聚丙烯酰胺作为滑溜水压裂液减阻剂的应用性能研究

以丙烯酰胺、丙烯酸和2-丙烯酰胺基-2-甲基丙烷磺酸作为亲水单体,再引入疏水单体R-8,使用水溶液聚合,获得了低摩阻、高粘弹性的疏水性缔合聚合物DR-8,用FTIR表征结构,分别通过管路摩阻测试系统和流变仪测试了DR-8在不同条件下的减阻性能及流变性能。结果表明,合成的聚合物与预期产品结构一致,当流速为3 m/s、浓度为1.2 g/L时,DR-8的减阻率为75.5%,具有良好的减阻性能,同时具有良好的黏弹性,能够满足非常规油气藏体积压裂、大排量施工、降低摩阻的要求,而且在载砂量方面明显优于常规滑溜水压裂液。     

疏水缔合聚丙烯酰胺作为滑溜水压裂液减阻剂的应用性能研究

以丙烯酰胺、丙烯酸和2-丙烯酰胺基-2-甲基丙烷磺酸作为亲水单体,再引入疏水单体R-8,使用水溶液聚合,获得了低摩阻、高粘弹性的疏水性缔合聚合物DR-8,用FTIR表征结构,分别通过管路摩阻测试系统和流变仪测试了DR-8在不同条件下的减阻性能及流变性能。结果表明,合成的聚合物与预期产品结构一致,当流速为3 m/s、浓度为1.2 g/L时,DR-8的减阻率为75.5%,具有良好的减阻性能,同时具有良好的黏弹性,能够满足非常规油气藏体积压裂、大排量施工、降低摩阻的要求,而且在载砂量方面明显优于常规滑溜水压裂液。     

Study on preparation and self-assembly properties of hydrophobically associating polyacrylamide by emulsifier-free ultrasonic assisted radical polymerization

Through ultrasonic assisted radical polymerization, hydrophobically associating polyacrylamide (U-HAPAM) was prepared by acrylamide (AM), 2-acrylamido ?2- methyl propane sulfonic acid (AMPS), and hydrophobic monomer octadecyl acrylate (ODA). The effects of concentration of initiator, ultrasonic frequency power and concentration of total monomers, had great influences on total monomer conversion, relative molecular mass and the viscosity of its aqueous solution. The macroscopic and microscopic self-assembly behaviors of the product was studied through apparent viscometry, fluorescence spectroscopy(FS) and atomic force microscope(AFM) respectively. The results showed that, the ultrasound possessed the certain ability of initiating and 0.3 % of initiator was advisable to use during the ultrasonic assisted radical polymerization to enhance the efficiency without substantially affecting the M_w; the thickening ability of the product was best under120W ultrasonic frequency power, of which the apparent viscosity attained 153.3 mPa?·?s as the concentration of U-HAPAM was 0.30 wt.%. Weighting the reaction efficiency and M_w, the concentration of total monomers was set as 10 % optimally. U-HAPAM achieved more excellent self-assembly performance and the critical association concentration of U-HAPAM prepared under these conditions was 0.27 wt.% (CAC) obtained from apparent viscometry and 0.23 wt.% (CAC') from FS.     

Study on preparation and solution properties of hydrophobically associating polyacrylamide by emulsifier-free ultrasonic assisted radical polymerization

Removal of heavy metals from aqueous solutions has attracted much attention worldwide. Many processes and technologies have been developed to remove heavy metals ions. In our previous study, a silica-poly acrylic amphoteric hybrid hydrogel was successfully prepared with double-network (DN) structure using ??-aminoporpyltriethoxysilane as precursor through a two-step sequential network formation technique. In the present research, the absorption behavior of this hydrogel was investigated carefully using Cu²⁺ ions and Cr₂O ₇ ^2? ions as representatives of negative and positive ions respectively. Under different adsorption conditions, the adsorption behaviors of the hydrogel were studied in detail, including initial concentration of the adsorbed ions, adsorption time, pH and ionic strength. The results showed the absorption capacity to Cu²⁺ can reach 700?mg/g with an initial Cu²⁺ concentration of 1,200?mg/L within 2?h. The experimental results show that the Freundlich adsorption law is applicable to the adsorption of Cu²⁺ and Cr₂O ₇ ^2? on the hydrogel.