兼有离子和疏水缔合两种结构特性的聚丙烯酰胺的缔合性能

合成了新型的表面活性单体二甲基十四烷基（2-丙烯酰胺基丙基）溴化铵（DTAB）,并将该单体与丙烯酰胺在水溶液中自由基均相共聚得到了兼具离子基团和疏水基团的阳离子疏水缔合丙烯酰胺共聚物p(DTAB-co-AM)。通过表观黏度法和芘荧光探针法研究了DTAB含量、NaCl、十二烷基硫酸钠（SDS）和十六烷基三甲基氯化铵（CTAB）对共聚物缔合性能的影响。结果表明：当DTAB含量为0.3%(摩尔)时,共聚物呈盐增黏特性,在1%（质量）的盐溶液中,其临界缔合浓度由纯水中的0.15 g·dL^-1降至0.11 g·dL^-1;当DTAB含量小于0.3%（摩尔）时,仅在浓度大于5%（质量）的盐溶液中具有盐增黏特性。该共聚物与SDS作用,在疏水缔合和静电吸引两种作用下,缔合后体系的黏度最大可增加136倍,由缔合前的12 mPa·s增加到1634 mPa·s,而与CTAB作用,由于只有疏水缔合作用,缔合强度较弱黏度增加不大。     

丙烯酰胺/丁基苯乙烯共聚物组成的非均匀性

以疏水缔合效应强于苯乙烯的丁基苯乙烯(BST)为疏水单体,采用自由基胶束共聚合方法合成了丙烯酰胺(AM)/丁基苯乙烯(BST)疏水缔合水溶性共聚物(简称:PSAM)。采用元素分析测定PSAM的组成,通过直线截距斜率法得到AM和BST的竞聚率分别为0.76和8.55,说明BST的均聚反应活性较大,导致了BST疏水链段在共聚物分子中的分布存在着非均匀性,而且随着共聚合转化率的增加,这种共聚物组成的非均匀性对共聚物的增粘性能有很大的影响。当Cp=0.3 g/dL时,共聚合转化率分别为20.27%和89.07%的共聚物的溶液表观粘度分别为1283 mPa.s和296mPa.s。     

一种具有表面活性的双尾疏水缔合丙烯酰胺共聚物

文章以自制双尾疏水丙烯酰胺单体丙烯酰胺(N-苄基-N-辛基丙烯酰胺,N-benzyl-N-octylacrylamide,BOAM)和表面活性单体(辛基酚聚氧乙烯醚丙烯酸酯,OP-10-AC)与丙烯酰胺(acrylamide,AM)水溶液共聚合成新型疏水缔合共聚物(AM-Na A-OP10AC-BOAM)。实验结果表明,当聚合物浓度大600mg/L时,表观黏度迅速增加,表现出明显的缔合行为;共聚合物溶液具有良好的黏弹性和表面活性,SEM扫描电镜照片显示共聚物溶液中存在网状的缔合微观形貌特征。     

表面活性剂对疏水改性丙烯酰胺共聚物增粘性能的影响

采用自由基胶束聚合法合成丙烯酰胺/丁基苯乙烯疏水缔合水溶性共聚物(PSAM),所用的十二烷基硫酸钠(SDS)、辛基酚聚氧乙烯醚(OP-10)和十六烷基三甲基溴化铵(CTAB)能显著影响疏水单体在聚合产物中的含量,从而影响聚合物的溶液粘度,其中以SDS合成得到的产物的溶解性及增粘性能最好。另外,少量表面活性剂的加入能显著地提高聚合物亚浓溶液的粘度,在十二烷基苯磺酸钠(SDBS)、SDS和CTAB中,SDBS对聚合物亚浓溶液粘度的影响最大,其浓度为0.7 mmol/L时,0.3 g/dL PSAM溶液的表观粘度从237 mPa.s上升到981 mPa.s。     

疏水缔合改性丙烯酰胺共聚物的合成

采用自由基胶束聚合法合成了丙烯酰胺（AM）/丁基苯乙烯（BS）/2-甲基-2-丙烯酰胺基丙磺酸钠（NaAMPS）疏水缔合水溶性共聚物PASA,PASA避免了目前疏水缔合聚合物溶液热稳定性差的问题.研究得到了适宜的反应条件,包括NaAMPS、BS和引发剂加量相对于单体总量的摩尔分数分别为10%、2.5%和0.07%,总单体在水里的质量分数为10%,SDS在水里的质量分数为6.0%,反应温度50℃,pH=6～7,反应时间12 h.采用以上反应条件得到PASA的临界缔合质量浓度为0.05 g·dL^-1,对应的水溶液表观黏度为283 mPa·s,质量浓度为0.1 g·dL^-1的水溶液表观黏度为1020 mPa·s.采用元素分析、UV、FT-IR和¹HNMR证实了共聚物的分子结构;DSC分析表明了共聚物分子链中存在疏水嵌段.     

驱油用疏水缔合聚合物临界缔合浓度的性能研究

对自制的用于高温高盐油藏驱油用疏水缔合聚丙烯酰胺(HAPAM)处于临界缔合浓度(CAC)上下的两个浓度的溶液进行了各项性能评价对比。结果表明,该HAPAM在高于CAC之上表现出优异的性能:当NaCl溶液质量浓度从70 000 mg/L增长到200 000 mg/L时,聚合物溶液的黏度增长30倍,在180 000 mg/L模拟盐水中,90℃时的黏度是30℃时的6.2倍,显示出良好的耐温抗盐性;在变剪切实验中显示良好的剪切恢复性;流变学研究表现出具有明显的黏弹性;岩心实验结果表明,高于CAC的聚合物注入压力传播更均匀。     

疏水缔合两亲共聚物的溶液性质及其在天然气水合物压裂中的应用

本文合成了新型疏水缔合两亲共聚物，并对其在溶液中的聚集行为和流变特性进行探究。结果表明：随着两亲单体含量的增加，共聚物表现出更低的临界缔合浓度(CAC)，可形成更大聚集数的聚集体，在25℃，剪切速率170 s^-1下，0.5%共聚物HPAE10-1溶液黏度达205 m Pa·s；触变实验表明疏水缔合作用形成了可逆的网状结构，这种网状结构使共聚物溶液具备了优异的黏弹性能，高频时表现出较高的储能模量和损耗模量；探索了HPAE10-1/有机锆组成的压裂液体系在天然气水合物压裂中的应用性能，发现其对不同粒径的支撑剂都具有良好的悬浮效果、有较低的滤失量，加入破胶剂后在125 min内可使压裂液黏度降低到5 m Pa·s。     

疏水缔合聚合物溶液的性能

疏水缔合水溶性聚合物指在常规水溶性聚合物主链上引入极少量疏水基团所形成的一类新型聚合物。与部分水解聚丙烯酰胺(HPAM)相比,这类聚合物的分子量不高,但具有独特的溶液性能。本文综述了疏水缔合聚合物的增黏、耐温、抗盐、抗剪切的溶液性能。     

压裂用疏水缔合聚合物溶液性质及减阻性能研究

摘要：以一种功能性疏水单体与丙烯酰胺（AM）、丙烯酸（AA）和2-丙烯酰胺-2-甲基丙磺酸（AMPS）为原料,合成了一种疏水缔合聚合物HAWP-18。采用流变仪考察了疏水缔合聚合物HAWP-18的耐剪切性能、黏弹性及触变性,结果表明,HAWP-18属于假塑性流体,临界缔合浓度为2.31g/L,表现出较强的耐剪切性能;黏弹性测试表明,HAWP-18是典型的黏弹性结构流体,具有较宽的线性黏弹区,该体系的储能模量G''大于损耗模量G'',并且黏度越大,弹性特征越强;采用稳态剪切测试研究了不同质量浓度HAWP-18的剪切应力与剪切速率的关系,HAWP-18具有触变性,并且触变性随质量浓度增大而增强;使用自制摩阻测试仪测定了不同质量浓度HAWP-1的减阻性能,结果表明,HAWP-18减阻率随质量浓度的增加先上升后降低。HAWP-18的耐剪切性及其良好的黏弹性、触变性和减阻性能为其应用于压裂液提供了实验支撑。     

疏水缔合型聚合物P(AM/TA)溶液性质的研究

采用沉淀聚合法制备了疏水缔合型聚合物丙烯酰胺 /丙烯酸十四酯共聚物P(AM/TA)。研究了在链结构中引入不同疏水基团摩尔分数的共聚物的溶液性质。结果表明该共聚物在w(NaCl) =1 5 %的溶液中的黏度较之水溶液有较大提高 ,表现出明显的抗盐性质 ,而临界缔合质量分数和特性黏度均出现下降趋势。该聚合物是一种性能优异的疏水缔合型增稠剂。作者对共聚物溶液的黏度 -温度性质和剪切速度对溶液黏度的影响也进行了研究。     

丙烯酰胺/丁基苯乙烯疏水缔合共聚物的合成与表征

以丁基苯乙烯(BS)为疏水单体,采用自由基胶束聚合法合成了丙烯酰胺(AM)/丁基苯乙烯(BS)疏水缔合水溶性共聚物(PSAM),来解决该类聚合物热稳定性较差的难题。研究得到了适宜的反应条件:n(K2S2O8)∶n(Na2SO3)=3∶1,引发剂和BS相对于单体总量的摩尔分数分别为0.06%和1.45%,总单体在水里的质量分数为20%,SDS在水里的质量分数为5.5%,pH=6~7,反应温度50℃。采用该反应条件得到PSAM的临界缔合质量浓度为1 g/L,对应的水溶液表观黏度为21 mPa.s;质量浓度为2 g/L时,对应的水溶液表观黏度为78 mPa.s;质量浓度为1 g/L和2 g/L的PSAM在浓度为0.137 mol/L的NaC l水溶液中,于80℃老化120 d后的表观黏度分别为11.8 mPa.s和49.3 mPa.s,黏度保留率分别为42.1%和45.1%。通过元素分析、UV、FTIR表征了PSAM的分子结构;DSC分析表明PSAM为嵌段共聚物,两个玻璃化转变温度分别为BS链段的106℃和丙烯酰胺链段的203℃。     

Rheological behaviors and structure of hydrophobically associating AM–SMA copolymers synthesized by microemulsion polymerization

A series of hydrophobically associating copolymers of acrylamide and hydrophobic stearyl methacrylate as comonomers were prepared by microemulsion polymerization. The rheological properties of the copolymers in aqueous solution depended on the content of hydrophobic monomer, initiator amount, surfactant concentration, the copolymer concentration and the addition of salt. The hydrophobically associating copolymers showed good temperature, shear, and salt resistance with the critical aggregation concentration around 0.6 g dL^?1. In addition, the apparent viscosities of hydrophobically associating copolymer solutions are increased remarkably by the addition of a small amount of NaCl and CaCl₂, respectively. FTIR and ¹H-NMR spectra indicate the structure of hydrophobically associating copolymers. The shear-thinning behavior of hydrophobically associating copolymer makes it useful in enhanced oil recovery and drilling fluids.     

疏水改性阳离子型丙烯酰胺共聚物的微结构与絮凝性能

用自由基胶束聚合法合成了丙烯酰胺（AM）/丁基苯乙烯（BS）/二甲基二烯丙基氯化铵（DMDAAC）疏水缔合型高分子絮凝剂PBAD。通过UV、FT-IR表征了共聚物的分子结构,AFM研究表明,由于丁苯基疏水基团强的分子间作用,0.005 g.dL-1 PBAD在水溶液中已形成了缔合体,并随着聚合物浓度的增加,缔合结构的尺寸和数量显著增加。在3%硅藻土溶液中,PBAD絮凝的最佳用量为0.005 g.dL-1,此时的透光率为96.5%,污水中的NaCl浓度能明显影响聚合物的架桥吸附作用,Ca2+和Al3+能增强聚合物的絮凝效果。     

Study on the rheological behavior of the hydrophobically modified hydroxyethyl cellulose with 1,2‐epoxyhexadecane*

Through the macromolecule reaction method, the hydrophobically modified hydroxyethyl cellulose (EP16–HAHEC) was synthesized using 1, 2‐epoxyhexadecane as the hydrophobic monomer. The solution properties of EP16–HAHEC were comprehensively investigated, which showed that the polymer with enhanced; viscosification property, thermal stability, shear resistance, and salt resistance was obtained. Amphiphilic structure of EP16–HAHEC molecules contributed to the surface activity of the polymer. By forming complex solution with surfactants or carboxylmethyl cellulose (CMC), the viscosification property of EP16–HAHEC could be enhanced through the interactions of hydrophobic groups and hydrogen bonds. The viscosity‐enhancing mechanism of HAHEC was studied by the environment scan electronic microscope (ESEM) and the fluorescence spectrum measurements, which demonstrated that the formation of the supramolecular aggregation networks was coincident with the increase of the apparent viscosity of HAHEC. With the gradual formation of the complete polymer molecule networks, the apparent viscosity rised dramatically, and the associating aggregations of the polymer molecules appeared far before the great change of the macroproperty of the polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2953–2959, 2006     

Study on the morphology of the novel hydrophobically associative acrylamide‐based terpolymer in aqueous solution by AFM measurements

The synthesized hydrophobically associating water‐soluble polymer P(AM‐BST‐NaAMPS) (PASA) exhibits good viscosification properties in the aqueous and brine solution. To study the viscosifying mechanisms of the polymer in the aqueous solution and brine solution, atomic force microscope (AFM) was applied to observe the micromorphology of the polymer solution. The AFM measurements show that continuous network structures have been formed in the aqueous solution of 0.05 g dL^?1 PASA, and with the increase in PASA concentration, the network structures become much bigger and more condensed. The network structures of PASA are collapsed by the addition of salt, and tree‐like crystals are formed, leading to the decrease in the apparent viscosity of PASA solution. However, by increasing the NaCl concentration or the polymer concentration in the brine solution, the sizes of crystals increase. These results are consistent with the ESEM and viscosity study results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3996–4002, 2006     

疏水缔合水溶性聚合物P(AM/NaAA/DiAC14)水溶液的黏度行为

采取前加碱二元胶束共聚-共水解法合成了三元疏水缔合水溶性聚合物聚(丙烯酰胺/丙烯酸钠/N,N-双烯丙基十四胺)〔P(AM/NaAA/D iAC14)〕,研究了其水溶液的黏度行为。当x(D iAC14)=0.10%~0.40%时,在30℃、c(NaC l)=1 mo.lL-1水溶液中,P(AM/NaAA/D iAC14)的特性黏数[η]、黏均相对分子质量Mη、Huggins常数KH、平均线团密度ρequ分别为18.88~22.22 dL.g-1、9.98×106~12.24×106g.mol-1、0.117~0.299和0.112~0.132 g.dL-1;KH小于0.8,表明其分子内缔合作用较弱。P(AM/NaAA/D iAC14)在矿化度为19 334μg.g-1盐水溶液中的表观黏度随疏水单体摩尔分数的增加而增加,随温度、剪切速率的增加而降低。在NaC、lCaC l2的离子强度分别为1.26×10-3~4.88×10-3mol.kg-1、1.073×10-4~5.28×10-4mol.kg-1的水溶液中,P(AM/NaAA/D iAC14)出现盐增黏现象,疏水单体摩尔分数越大,盐增黏效应越显著。随疏水单体摩尔分数的增加,临界缔合质量浓度(CAC)降低;与后加的十二烷基硫酸钠(SDS)〔ρ(SDS)=0~0.07 g.dL-1〕的疏水缔合作用增强,黏度增加的幅度增大。     

Synthesis,characterization, and solution properties of a surface‐active hydrophobically associating polymer

A nonionic surfmer (MAA‐EO₂₃C₁₂) was prepared and reacted with acrylamide, acrylic acid, and a double tailed hydrophobic monomer (BTMAM) to synthesize a surface‐active hydrophobically associating copolymer (SHAP) through photoinitiated free radical copolymerization in aqueous solution. Fourier transform infrared and ¹H‐nuclear magnetic resonance spectroscopy were used to characterize the functional monomer and the SHAP. Several performance evaluations, such as viscosification property, temperature resistance, salt tolerance, and shear resistance, were also conducted. Experiment results demonstrated that the introduced nonionic surfmer and hydrophobic monomer could endow the copolymer with excellent temperature resistance, salt tolerance, and shear resistance capability at low concentration. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46569.     

AM/AMPS/SMA三元共聚物的合成及其性能研究

采用自由基胶束聚合法制备了丙烯酰胺/甲基丙烯酸十八酯/2-甲基-2-丙烯酰胺基丙磺酸三元疏水缔合共聚物(HAPAM),系统研究了HAPAM水溶液的流变行为。结果表明,在聚丙烯酰胺大分子主链上引入阴离子基团和疏水基团后。阴离子的电粘效应与疏水基团的疏水缔合作用相互协同作用,使得共聚物水溶液的粘度明显提高;盐溶液对疏水缔合作用的增强效应与阴离子基团的耐盐性相互结合,使HAPAM水溶液的抗盐性能得以明显提高;HAPAM在水溶液中可以有效的形成大量疏水微区,因而具有较好的耐温耐盐和增粘性能。